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Welcome to Microbiology at Delta College!

Bio 203, General Microbiology & Infection Control

Joyce Howard, Delta College 

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Bio 203, General Microbiology & Infection Control
Exam One Lecture Notes 

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These lecture notes are a compilation of the information you are learning through your assignments. It has been organized here to assist you with preparation and study for Exam One.

From orientation assignment, Doing Assignments Online:

Services of the CDC:

• The CDC:
• CDC stands for the Centers for Disease Control and Prevention. It is located in Atlanta, Georgia.
• The CDC is recognized as the lead federal agency for protecting the health and safety of people - at home and abroad, providing credible information to enhance health decisions, and promoting health through strong partnerships.
• The CDC serves as the national focus for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of the people of the United States.

• HICPAC:
• HICPAC stands for the Hospital Infection Control Practices Advisory Committee.
• HICPAC was established in 1991 to provide advice and guidance to the Secretary, Department of Health and Human Services (DHHS); the Assistant Secretary for Health, DHHS; the Director, CDC; and the Director, National Center for Infectious Diseases, regarding the practice of hospital infection control and strategies for surveillance, prevention, and control of nosocomial infections in US hospitals.

• HCWs:
• Healthcare workers refers to all paid and unpaid persons working in healthcare settings who have the potential for exposure to infectious materials, including body substances, contaminated medical supplies and equipment, contaminated environmental surfaces, or contaminated air.
• These personnel may include, but are not limited to, emergency medical service personnel, dental personnel, laboratory personnel, autopsy personnel, nurses, nursing assistants, physicians, technicians, therapists, pharmacists, students and trainees, contractual staff not employed by the health care facility, and persons not directly involved in patient care but potentially exposed to infectious agents.

• MMWR:
• The Morbidity and Mortality Weekly Report (MMWR) is a weekly series prepared by the Centers for Disease Control and Prevention (CDC).
• The data in the weekly MMWR is provisional, based on weekly reports to the CDC by state health departments.
• The reporting week concludes at the close of business on Friday.  Data compiled on a national basis is officially released to the public on the succeeding Friday.
• As needed the MMWR publishes Recommendation and Reports , which are reports on special issues involving health and safety.

Bacterial Cell Shapes:

• There are 3 basic shapes:  round (coccus/cocci); rod (bacillus/bacilli); spiral (spirochetes).
• The shape of the bacterium is determined by the type and extent of cross-linking in the peptidoglycan layer of its cell wall.
• Pleomorphic bacteria show variations in shape and size due to variations in their cell wall structure.

• The functions of the cell wall is to hold the cell together (give it rigidity), protect the cell from damage, and determine the shape of the cell.

• The Gram Positive Cell Wall:
• Examples of Gram positive bacteria are Staphylococcus and Streptococcus.
• The main featureof the Gram positive cell wall is its thick peptidoglycan layer. Makes up 50% of the weight of the Gram positive bacterial cell. The peptidoglycan structure is composed of n-acetyl muramic acid & n-acetyl glucosamine with peptide crosslinks. The crosslinks are made of D-glutamic acid, D-alanine, and DAP (diaminopimelic acid). The Gram positive cell wall also contains techoic & lipotechoic acids, whose function is unclear.

• The Gram Negative Cell Wall:
• Examples of Gram negative bacteria are Escherichia (you're used to hearing E. coli ) and Pseudomonas .
• The Gram negative cell wall contains an outer membrane (known as LPS layer), thin peptidoglycan layer, and the periplasmic space.
• The LPS layer (lipopolysaccharide) is a phospholipid bilayer with porins. The LPS contains core polysaccharides, O polysaccharide side chains (known as the O antigens), and lipid A (known as the endotoxin).
• O antigens stimulate immune antibody response.
• Lipid A, when released from dying cells, functions as an endotoxin.

• Wall-less Bacteria:
• An example of a wall-less bacterium is Mycoplasma pneumoniae, which causes "walking pneumonia."
• These bacteria have no cell walls. To compensate, they have a more sturdy cell membrane.
• They are pleomorphic, capable of rapid shape changes.

• The O antigens on the outside of the Gram negative cell wall are one example of antigens.
• Antigens are the small structures on the outside of bacteria (and other micoorganisms) to which your immune system responds.
• Your immune system responds to antigens by making antibodies specific to the antigen which stimulated them.
• Antigen-antibody response is known as humoral immunity and is made by B cells.
• Cell-mediated immunity (also called cellular immune response) is made by T cells.
• Macrophages and dendritic cells (also called antigen-presenting cells) present the antigens from bacteria (and other microorganisms) to B cells and/or T cells to initiate the two types of responses.
• Acquired immune response:
• Is highly specific (i.e., specific to the antigen which stimulated the response).
• Includes memory (i.e., further exposure will elicit a more faster response).
• Involves both B cells (i.e., antibody response) and T cells (i.e., cell-mediated response) which act together with macrophages and dendritic cells.

• When Gram negative bacteria divide or die, the lipid A portion of the LPS layer of their cell wall is released and becomes toxic to the host. It is known as an endotoxin.
• When released, endotoxins bind to macrophages. This binding causes the macrophages to release the cytokine known as interleukin-1 (IL-1).
• IL-1 causes the symptoms experienced by the patient, including fever, weakness, and aching. If left untreated, this may result in shock.
• Endotoxins are heat-stable (i.e., resistant to heat), therefore are not destroyed through autoclaving.

• Exotoxins are soluble poisonous substances produced and released by living bacterial cells.
• Exotoxins are produced by most Gram positive and Gram negative bacteria.
• Exotoxins are some of the most potent poisons known to mankind.
• Exotoxins produce the major symptoms and complications of disease.
• Many bacteria produce not just one, but several of these destructive exotoxins! The more exotoxins a bacterium produces, the more harmful that bacterium is!
  
• Major types of exotoxins include:  A-B Exotoxins, Membrane-Damaging Exotoxins, and Superantigen Exotoxins.
• A-B Exotoxins cause the destruction associated with the following diseases: Diphtheria, Cholera, Tetanus, and Dysentery. The A portion is the destructive protein or enzyme, while the B portion is what binds to the person's cells. We will study these destructive A-B exotoxins as we learn about the particular diseases in which they play a major role.
• Membrane-Damaging Exotoxins are also destructive cytolytic proteins or enzymes. (They don't have A-B portions.) These cytolytic exotoxins break up the cell membrane, leading to lysis of the cell. The alpha-toxin produced by Clostridium perfringes in Gas Gangrene is such an exotoxin. 
• Superantigen Exotoxins are destructive antigenic proteins that are activated in certain T-cell responses to disease. They cause an overstimulation of the T-cell response. Normally only .01% on T-cells are activated in a T-cell response. With a superantigen exotoxin, 2-20% of the T-cells become activated! This causes the release of high amounts of the cytokines produced by the T-cells, leading to major destruction. The consequences can be life-threatening! We will learn more about superantigens later in the semester.
• Exfoliatin is a destructive protein exotoxin produced by some strains of Staphylococcus aureus causing Scalded Skin Syndrome. Exfoliatin destroys the substance binding together layers of the skin, causing the outer layer to separate.

• A slime layer is a loose, unorganized glycocalyx.
• The slime layer allows colonies of bacteria to become attached.  The network of polymer comprising the slime layer becomes a biofilm. The biofilm is formed in order to allow colonies to survive under many conditions of eradication.
• In healthcare, a slime layer forms a biofilm on catheters (urine or heart), pacemakers, and artificial heart valves.
• Staphylococcus epidermidis only produces its slime layer when it has the opportunity to attach to a catheter or other instrument.
• A slime layer (biofilm) protects the bacterium against host defenses (mechanical flushing, cell-mediated immunity, and antibody-mediated immunity). It hides the bacterium from your immune system cells.
• A slime layer (biofilm) also protects the bacterium against antibiotics, chemicals, and radiation.
• 65% of all bacterial infections are estimated to involve the formation of biofilms.
• Gram positive bacteria associated with biofilm formation on indwelling medical devices include Enterococcus faecalis, Staphylococcus aureus , Staphylococcus epidermidis , and Streptococcus viridans.
• Gram negative bacteria associated with biofilm formation on indwelling medical devices include E. coli, Klebsiella pneumoniae, Proteus mirabilis , and Pseudomonas aeruginosa.
  

• A capsule is a firm, organized glycocalyx.
• Capsules are important in bacterial virulence. They protect the bacteria from phagocytosis by the host's cells.
• This means that when the bacteria get in your body, your immune system cells cannot locate and bind to them.
• Because they are not readily destroyed, illnesses caused by encapsulated bacteria tend to be more severe.
• Capsules can also be used for attachment within the body.
• Capsules protect the bacteria against dehydration. They can be broken down and used as a food source to help bacteria survive harsh environmental conditions.
• Encapsulated Streptococcus mutans attaches to teeth & causes dental caries.
• Virulence describes attributes of a microorganism that promote pathogenicity, which is the ability to cause disease. Avirulence means  non-disease causing.
• Encapsulated Streptococcus pneumoniae is virulent and causes pneumonia.
• Nonencapsulated Streptococcus pneumoniae is avirulent and doesn't cause pneumonia.

• Fimbriae are short, bristle-like, appendages and are used for adherence (attachment).
• Fimbriae can occur at the poles (ends), or be evenly distributed over the whole bacterial cell.
• Bacteria can have a few to hundreds of fimbriae.
• Fimbriae are usually found on Gram negative bacteria.
• Examples of bacteria who use fimbriae for adherence (attachment) are :
• Moraxella catarrhalis : Uses fimbriae to attach in the respiratory tract and causes chronic bronchitis.
• Neisseria gonorrhoeae : Uses fimbriae to attach in the genitourinary tract and causes gonorrhea.

• Sex pili are longer, larger, and less numerous than fimbriae.
• Sex pili are only found on Gram negative bacteria.
• Sex pili are used in conjugation.
• Conjugation involves the transfer of plasmids between bacteria through the sex pilus.
• Bacteria pass antibiotic resistance, plus other forms of resistance, to each other through conjugation.
• An example of a Gram negative bacteria that shares genetic information via conjugation is E. coli.

• Flagella are for motility. Bacteria with flagella are said to be motile.
• Types of flagellation: monotrichous (one flagellum), lophotrichous (many flagella at one end), amphitrichous (flagella at both ends), or peritrichous (flagella located over the whole bacterial cell).

• The Five Kingdoms are: Prokaryotae, Protista, Mycetae (Fungi), Plantae, and Animalia.
• Bacteria comprise the Kingdom Prokaryotae (also spelled Procaryotae ).  It is also called Monera.
• Cells are prokaryotic and unicellular.
• Bacteria have only a nucleoid, also called the chromatin body.  They do not have a "true nucleus" because they do not have a nuclear envelope (membrane).
• Bacteria have just one long circular chromosome. It is composed of double-stranded DNA.
• The Kingdom includes Gram positive bacteria, Gram negative bacteria, Mycoplasma, Archaeobacteria , and Cyanobacteria.
• All bacterial infections come from this Kingdom!
• Protozoans comprise the Kingdom Protista.
• Cells are eukaryotic and mostly unicellular.
• Examples of protozoans: Euglena , Paramecium, and Amoeba.
• Amoebic Dysentery, Giardiasis, and Cryptosporidiosis are diseases associated with this Kingdom.
• Fungi, molds and yeasts comprise theKingdom Mycetae, also known as Fungi .
• Cells are eukaryotic and mostly multicellular.
• Ever had a yeast infection? HIV patients are subject to many fungal infections.
• Flowers, trees, mosses, and all other plants comprise the Kingdom Plantae.
• Cells are eukaryotic and multicellular. Their cells display tissue differentiation & specialization.
• We will not deal with any plant infections in this course.
• Man and animals comprise the Kingdom Animalia.
• Cells are eukaryotic and multicellular. Their cells display tissue differentiation & specialization.

• The microbial world includes living organisms and nonliving infectious agents.
• All bacteria, which are prokaryotes.
• Fungi , protozoa, algae, and helminths, which are eukaryotes.
• Acellular, nonliving agents, which include viruses, viroids, and prions.

• Viruses:
• Viruses are acellular nonliving agents. They contain some form of nucleic acid (DNA or RNA) surrounded by a protein coat.
• Viruses are obligate intracellular parasites. They must live inside of a host cell and use that host cell's machinery to reproduce and survive. They usually destroy the host cell upon their exit.
• Viruses can infect bacteria, protozoa, fungi, plants, animals, and humans.

• Viroids:
• Viroids are acellular nonliving agents. They are short strands of RNA. They do not have protein coats.
• Viroids are obligate intracellular parasites.
• So far only viroids that infect plants have been found.

• Prions:
• Prions are acellular nonliving agents. They are made of proteins. They do not contain nucleic acids.
• Prions are obligate intracellular parasites.
• In humans, they have been found to cause slowly progressive neurological diseases, such as Kuru and CJD (Creutzfeld-Jakod disease).
• "Mad Cow Disease," found in the United Kingdom and Europe, is a prion disease of both cows and humans.
• Chronic Wasting Disease is a prion disease of deer and elk herds.
  
• Prions are not destroyed by our usual methods of sterilization and disinfection!! 
• CJD has been accidentally transmitted on instruments in surgery. 
• Neurosurgeons & neuropathologist are at risk. 
• Every year app. 200 people die in the U.S. from CJD.
• According to WHO (World Health Organization) guidelines, all disposable instruments, materials, and wastes that come in contact with high infectivity tissues (brain, spinal cord, and eyes) and low infectivity tissues (cerebrospinal fluid, kidneys, liver, lungs, lymph nodes, spleen, and placenta) of suspected or confirmed TSE patients should be disposed of by incineration.
• According to WHO, surfaces and heat-sensitive re-usable instruments that come in contact with high infectivity and low infectivity tissues should be decontaminatedby flooding with or soaking in 2N NaOH or undiluted sodium hypochlorite for 1 hour and rinsed with water.
  [CDC NOTE: Sodium hypochlorite may be corrosive to some instruments.]
• According to WHO, the three sterilization methods for heat-resistant instruments are listed below. Before instruments are immersed in sodium hypochlorite, the instrument manufacturer should be consulted about the instrument's tolerance of exposure to sodium hypochlorite.
• Immerse in a pan containing 1N sodium hydroxide (NaOH) and heat in a gravity displacement autoclave at 121°C for 30 min; clean; rinse in water; and subject to routine sterilization.
  [CDC NOTE: The pan containing sodium hydroxide should be covered, and care should be taken to avoid sodium hydroxide spills in the autoclave. To avoid autoclave exposure to gaseous sodium hydroxide condensing on the lid of the container, the use of containers with a rim and lid designed for condensation to collect and drip back into the pan is recommended. Persons who use this procedure should be cautious in handling hot sodium hydroxide solution (post-autoclave) and in avoiding potential exposure to gaseous sodium hydroxide, exercise caution during all sterilization steps, and allow the autoclave, instruments, and solutions to cool down before removal.]
• Immerse in 1N NaOH or sodium hypochlorite (20,000 ppm available chlorine) for 1 hour; transfer instruments to water; heat in a gravity displacement autoclave at 121°C for 1 hour; clean; and subject to routine sterilization.
  [CDC NOTE: Sodium hypochlorite may be corrosive to some instruments.]
• Immerse in 1N NaOH or sodium hypochlorite (20,000 ppm available chlorine) for 1 hour; remove and rinse in water, and then transfer to open pan and heat in a gravity displacement (121°C) or porous load (134°C) autoclave for 1 hour; clean; and subject to routine sterilization.
  [CDC NOTE: Sodium hypochlorite may be corrosive to some instruments.]

• The binomial system of nomenclature refers to a two-word naming system.  The first word is the genus, such 
as Escherichia, and the second word is the species name, such as coli.
• The first letter of the genus name is always capitalized.  The species name is never capitalized.  When typed, both genus and species are italicized.
• Once the genus-species name of a microorganism is introduced in a discussion, such as Streptococcus pneumoniae, it is OK to abbreviate the genus name in the continued discussion, such as S. pneumoniae .
• Bacterial strains have the same name because they are of the same species.  They differ in minor ways that may not constitute a different species name, so it is given a different strain designation.
• The word "streptococcus" means a chain of cocci.
• The word "diplococcus" means cocci that occur in pairs.
• The word "staphylococcus" means a cluster of cocci (which look like a cluster of grapes).

• Stains:
• A stain is a dye made into a solution, an aqueous (water) or alcohol solution, and used to treat a specimen for microscopic examination.
• A dye is a salt composed of positive and negative ions.  One of the ions (the positive or the negative) is colored.
• The colored ion is called the chromophore, or color-bearing ion.
• In basic dyes the chromophore is the positive ion.  Basic dyes include methylene blue, crystal violet, safranin, malachite green and carbolfuschin.
• In acidic dyes the chromophore is the negative ion.  Acidic dyes include eosin, nigrosine, and India ink.

• Simple Staining Procedures:
• Simple staining procedures can be positive or negative staining procedures.  They involve the use of just one dye in the staining process.
• Positive staining procedures use a basic dye, meaning the chromophore is the positive ion.
• Bacteria carry a slightly negative charge and respond best to basic dyes.
• The chromophore (positively charged) of the basic dye is attracted to the bacterial cells (negatively charged) and colors the cells (i.e., opposite charges attract).
• Basic dyes used in positive staining procedures include methylene blue, crystal violet, safranin, malachite green and carbolfuschin.
• Negative staining procedures use an acidic dye, meaning the chromophore is the negative ion.
• Since bacteria also carry a negative charge, the dye and the bacteria repel one another (i.e., like charges repel).
• As a result, the background is stained instead of the bacteria.  Another name for this procedure is background staining, since that is what is stained.
• Acidic dyes used in negative staining procedures include eosin, nigrosine, and India ink.

• Differential Staining Procedures:
• Differential staining procedures involve the use of two basic dyes in the staining process.  Two dyes are used to distinguish between bacteria or bacterial forms (such as vegetative cells and endospores).
• Because of their differences, some of the bacteria (or bacterial forms) will retain the color of one of the dyes, while other bacteria (or bacterial forms) will retain the color of the second dye used in the procedure.
• In a differential staining procedure:
• The primary stain initially colors both types of bacterial cells (or bacterial forms).
• The mordant increases the affinity of the primary stain for one type of bacteria (or bacterial form) by creating an insoluble compound. After the application of the mordant, both types of bacterial cells (or bacterial forms) still retain the initial color of the primary stain.
• The decolorizing agent causes a violent action which disrupts one type of bacterial cell (or bacterial form), causing the primary stain to be lost and the bacterial cells (or bacterial forms) to become colorless.
• The counterstain, or secondary stain, is added to stain the cells (or bacterial form) which has now become colorless.
• Examples of common differential staining procedures are the Gram stain, the acid fast stain, and the endospore stain.

• Gram Staining:
• The Gram stain was developed by Hans Christian Gram, a Danish bacteriologist, in 1883. As with other differential staining procedures, it involves the use of stains of at least two different colors.
• The primary stain is crystal violet, which initially colors all the bacterial cells a purple-blue color.
• The mordant is Gram's iodine, which increases the affinity of the primary stain for the specimen by creating an insoluble compound. After the application of the mordant, all cells remain purple.
• 95% ethyl alcohol is used as the decolorizing agent because of its violent effect upon lipids. Gram negative bacteria, with their outer LPS (lipopolysaccharide) layer are most effected by the alcohol. The LPS layer is destroyed, causing the primary stain to be lost and the Gram negative cells to become colorless.
• The counterstain, or secondary stain, is added to stain the Gram negative cells. Safranin, which has a pink-red color, is used to give a nice contrast.
• The Gram-positive bacteria end up purple and the Gram-negative bacteria end up pink.

• Gram Stain Procedure:
• Make a bacterial smear. This is a differential staining procedure., which means both cultures must be placed into the same target circle so that you will be able to view the differences.
• Flood the smear with crystal violet stain and allow the stain to remain on the slide for one minute.
• Wash off the stain by rinsing briefly (five seconds) with water from the wash bottle.
• Flood the smear with Gram's iodine and allow to remain for one minute.
• Wash off the stain by rinsing briefly (five seconds) with water from the wash bottle.
• Decolorize drop-by-drop with 95% ethyl alcohol while holding the slide on a diagonal.
• The timing of this step is most critical! Only decolorize from 10 - 20 seconds!
• The solvent should flow colorlessly from the slide when you have completed decolorization.
• Wash off by rinsing briefly (five seconds) with water from the wash bottle.
• Counterstain by flooding the smear with safranin and allowing to remain for one minute.
• Wash off the stain by rinsing briefly (five seconds) with water from the wash bottle.
• Place a packet of bibulous paper on the counter. Place the slide between sheets of the paper and gently blot the excess water from the slide.
• View the slide using the correct microscope procedure. You will want to view under low, high-dry, and then proceed to viewing with the oil immersion lens.

Things to think about when Gram staining:
• The age of the culture you used for the Gram stain procedure is important! We usually use young cultures that are between 16 - 24 hours old.
• Older cultures of Gram-positive bacteria may show a mixture of purple and pink cells.
• Older cells no longer resist the effects of decolorization and lose their purple color.
• The older Gram-positive cells are stained by the counterstain and appear pink.
• Critical thinking is necessary whenever you are interpreting results! Age of culture, or whether it is a spore-former, are facts that must be considered in your decision!

• Medical Importances Of The Gram Stain:
• The Gram stain is the most frequently used bacterial test in the health care profession.
• Usually when a specimen is taken from a patient, the Gram stain is part of the battery of tests that are run on that specimen. This battery of tests is referred to as "C & S Testing."
• All microbiologists (clinical, academic, industrial, etc) use the Gram stain in the identification process of a microorganism.
• The second vital piece of information gained through the Gram stain deals with patient treatment regimens.
• Chemotherapy involves the treatment of infectious disease with chemical agents. Such agents are named according to the type of microorganism they work against.
• Antimicrobial agents (antibacterials or antibiotics) act upon bacteria, antituberculars act upon the specific bacteria causing tuberculosis, antivirals act upon viruses, antiprotozoals act upon protozoa, antimalarials act upon the specific protozoan causing malaria, and antifungals act upon fungi.
• The results of a bacterial Gram stain particularly help in determining the type of antimicrobial to use on the patient.
• Antibiotics work upon the bacterial cell by interfering with a vital process of the cell.
• The drug may work by disrupting the cell membrane, inhibiting synthesis of the bacterial cell wall, inhibiting the production of a needed enzyme, or inhibiting DNA replication.
• Antibiotics which inhibit cell wall synthesis usually do so by inhibiting the synthesis of a specialized layer of the cell wall known as the peptidoglycan layer.
• Gram-positive bacteria have a rather thick peptidoglycan layer.
• Gram-negative bacteria have a chemically different and very thin peptidoglycan layer, covered by another layer known as the LPS layer.
• Therefore, antibiotics that inhibit cell wall synthesis work best against Gram-positive bacteria.
• These are some of the antibiotics which function by inhibiting cell wall synthesis: penicillins, vancomycin, bacitracin, and cephalosporins.
• The third vital piece of information gained through the Gram stain involves information about the type of infection present.
• When a clinical microbiologist does a Gram stain, it is a direct Gram smear of the patient's specimen.
• This means it will contain more than just the microorganism causing the infection.
• Normal body cells (often epithelial), normal flora (bacteria not suspected of causing the infection), and cells of the immune system (most commonly neutrophils and macrophages) could be present.
• To the clinician, this gives additional information about the type of infection.
• For instance, in a smear of cerebrospinal fluid, large numbers of macrophages indicate viral or fungal meningitis.
• But if the smear contains large numbers of neutrophils, this indicates bacterial meningitis.

• Bacteria reproduce by binary fission. The chromosome it duplicated, then the one parent cell divides into two daughter cells
• Nucleoid, or chromatin body, is the name for the nuclear area of the prokaryotic cell.
• Prokaryotes, or bacteria, have no nuclear membrane (also known as the nuclear envelope). Therefore, they do not have a true nucleus.
• Bacteria have one long, circular chromosome contained within their nuclear area.

• Plasmids are small cyclic DNA segments, composed if 5-100 genes.
• Plasmids replicate independently of the bacterial chromosome. Bacteria carry multiple copies of plasmids.
• R plasmids carry genes for toxin production, antibiotic resistance, enzymes, and tolerance to metals.
• Plasmids are passed between bacteria, usually through sex pili, in a process known as conjugation.

• Endospores are unique to bacteria. True endospores are only found in Gram-positive bacteria. The two genera that include most endospore formers are Bacillus and Clostridium .
• Endospores are highly durable, dehydrated cells with thick walls (called spore coats).
• Endospores can survive heat, lack of water, antimicrobial agents, chemicals and disinfectants, sunlight, ultraviolet radiation, and boiling.
• Extremely old endospores have germinated. Anthrax endospores over 1300 years old have been found.
• Endospores are a survival mechanism. It is not a reproductive process. There is no increase in cell numbers.
• Endospores form within a vegetative (parent) cell. One vegetative cell --- forms one endospore in order to survive --- which germinates into one vegetative cells when environmental conditions are again favorable.
• Endospores form via Sporulation or Sporogenesis.
• Endospores return to vegetative cells via Germination.

• Sporulation is triggered when environmental conditions become unfavorable and the bacterium needs to survive.
• Bacilli form spores aerobically and Clostridia form spores anaerobically.
• The endospore requires 10 to 15 hours to fully develop, to be able to fully survive the harmful environmental conditions.
• Stages in sporulation include: replication of bacterial chromosome, septum formation, forespore formation, formation of multilayered spore coat, and release of fully developed endospore from the dead vegetative cell.
• The heat resistance of endospores is due to high amounts of dipicolinic acid (DPA) and calcium, and its dehydrated form.
• The multilayered spore coat helps in resistance to chemicals and radiation.
• We must use a special endospore staining procedure in order to observe endospores under the microscope.

• Germination occurs rapidly, within 15 minutes, when environmental conditions become favorable.
• The endospore absorbs water, enlarges, and the spore coat disintegrates. The vegetative cell emerges.

Environmental Conditions of Bacteria:

• Temperature Ranges & Bacteria:
• Growth characteristics, such as temperature, are measured in ranges. Temperature ranges include:
• A minimal temperature, which is the temperature below which growth is impossible.
• An optimal temperature, which is the temperature at which growth reaches its maximum.
• A maximal temperature, which is the temperature above which growth is impossible.
• Thermophiles: Bacteria that live in warm temps. Optimal temp is above 40C.
• Mesophiles: Bacteria that live in moderate temps between 20 - 40C. Their optimal temp is usually body temp (37C).
• Psychrophiles: Bacteria that live in cold temps. Optimal temp is below 20C.

• pH Ranges & Bacteria:
• Growth characteristics, such as pH, are measured in ranges. pH ranges include:
• A minimal pH, which is the pH below which growth is impossible.
• An optimal pH, which is the pH at which growth reaches its maximum.
• A maximal pH, which is the pH above which growth is impossible.
• Acidophiles: Acid lovers. Optimal pH is below pH 5.5.
• Neutrophiles: Optimal pH is between pH 6 to pH 8.
• Alkalophiles: Alkaline lovers. Optimal pH is above 9.
• Acidoduric: Survives a stong acid environment for a short period of time. To endure!
• Acidotolerant: Tolerates a higher acid environment but prefer a more neutral environment.

• Salt Groupings & Bacteria:
• Halophiles: Salt lovers. Bacteria that require a very high concentration of salt to grow. These bacteria are found in the salt flats of Utah and the Dead Sea.
• Osmotolerant (also known as Halotolerant): Bacteria that tolerate a higher salt concentration, up to 10%, but prefer a lower salt environment. Staphylococcus living on the skin is an example.

• Oxygen Requirements & Bacteria:
• Obligate, or Strict, Aerobes: Require oxygen to live. Undergo aerobic cellular respiration.
• Obligate, or Strict, Anaerobes: Cannot grow in the presence of oxygen. Undergo anaerobic cellular respiration.
• Facultative Anaerobes: Prefer to undergo aerobic cellular respiration and live in an oxygen environment. However, when oxygen becomes depleted in their environment, they will switch to anaerobic respiration and continue to thrive.
• Aerotolerant Anaerobes: Tolerate oxygen but cannot use it.
• Microaerophiles: Require oxygen at a lower concentration than is what is normally found in air (21% concentration).

• Bacteria reproduce by binary fission. The chromosome it duplicated, then the one parent cell divides into two daughter cells.
• As a result of this, bacterial continually double in number. This is an exponential growth rate: a constant doubling in number.
• The time it takes the bacterium to go through its life cycle is known as its generation time. 
• For E. coli , its generation time is 10-20 minutes.
• For Mycobacterium tuberculosis, its generation time is > 12 hours.
  

• Bacterial Growth Curve includes these phases: lag phase, log growth phase, stationary phase, and log death phase.
• Lag Phase: Bacterial cells are adapting to the new habitat (media or host). R = D, or reproduction equals death.
• Log Growth Phase: Bacterial cells reproduce at their exponential rate (i.e., doubling). R > D, reproduction is greater than death. Bacteria display all their normal characteristics.
• Stationary Phase: A "limiting factor" begins to slow growth. (Ever run out of milk??) R = D.
• Log Death Phase: Bacterial cells are dying at an exponential rate. There's no more food and their waste products are building up. R < D, or reproduction is less than death.

• Lab Testing & the Bacterial Growth Curve:
• Lab tests are run during Log Growth Phase, when bacterial are displaying their normal characteristics. This is when you are to collect specimens and get them to the lab.
• Endospore stains are best done in late stationary and early death phase.

• Refrigeration & the Bacterial Growth Curve:
• Refrigeration extends or maintains the lag phase.
• Expiration dates on food and dairy products indicate the most likely date when the bacterial in the product are expected to move from the lag phase to the log growth phase. Products should be kept properly refrigerated and used before that date. If past the date, throw it out!
• Milk should be kept at 40F, or 5C. The "shelf life" will be cut the longer that milk is allowed to sit out on the counter! When milk (or other food products) warms up, the bacterial have the chance to move from lag phase to log growth phase even sooner.

• Definitions:
• Mixed population (culture): A culture which contains two or more types of organisms.
• Pure culture: A culture which contains only one strain of an organism.
• Sterile: Completely free of all microorganisms and viruses.  It is 100% free or it is not sterile!
• Aseptic techniques:  Techniques and procedures performed which ensure asepsis by preventing contamination of the work area, worker, and or the environment.
• Colony:  A population of bacterial cells all arising from a single bacterial cell.
• Agar: Ingredient used to solidify media used in the laboratory.
• Petri dish: Used in the laboratory for growth of bacterial colonies.

• Types of Media:
• Enriched media is general purpose media to which  we’ve added a special ingredient, something which is needed for the growth of the organism we are trying to isolate and identify.    Enrichment ingredients include blood, serum, hemoglobin, or a specific growth factor needed by a particular organism.
• Selective media has one or more ingredients (ex. dyes, salts, chemicals, or antibiotics) which inhibit the growth of certain organisms.  This allows the clinician to selectively grow only the organisms which are suspected to cause the infection for further study.
• Differential media contain indicators or ingredients that allow two or more different organisms to display a different, characteristic patterns of growth.  Two or more microorganisms grow on the same medium, but display very different, easily observable growth patterns.

• The surfaces of the body are inhabited by microorganisms which we call our normal flora.
• We live in a symbiotic relationship with these organisms. Some actually help protect us from harmful flora. We, in turn, provide them with a home, food, and a safe environment.
• These populations are also referred to as normal microflora, normal microbiota, and indigenous microbial populations.
• Objects that are frequently in contact with our bodies carry populations of our flora on their surfaces.
• These include jewelry, keys, and other items mentioned in the lab.
• In a health care setting, we transfer flora to bedding, chairs, eating utensils and other objects which we contact.

• Resident Flora:
• Resident flora are the regular, stable flora of the skin.
• They live in and colonize the deeper layers of the epidermis, hair follicles and glands.

• Transient Flora:
• Transient flora are acquired by routine contact and constantly vary.
• They are found only on skin surfaces and do not colonize.
• Since they are picked up by contact from infected persons or objects, they are highly influenced by personal hygiene.
• Oily skin, humidity, occupational exposure, and clothing are further influences to the composition of transient flora.

• Lower Respiratory: Trachea & bronchi have sparse flora; bronchioles & alveoli have no normal flora and are usually sterile.
• Gastrointestinal: Esophagus, stomach and upper portion of small intestine have no normal flora.
• Reproductive: No normal flora and usually sterile. Upper reproductive of female also sterile.
• Upper Urinary: Kidneys, ureters, bladder & upper urethra of both male & female have no normal flora and are usually sterile.
• Circulatory (Heart & blood vessels), Nervous (Brain & spinal cord), Muscular, Skeletal: No normal flora and usually sterile.
• Liver, glands, bone marrow, middle & inner ear, internal eye and sinuses: No normal flora and usually sterile.

• Cross Contamination: If you fail to wash your hands completely as you leave one patient or procedure and you  take contaminants with you to the next patient or procedure.
• Nosocomial Infection:  An infection that occurs within the health care setting.
• The patient did not "arrive"  with this infection, but gained it while in the health care setting due to lack of proper aseptic technique on the part of the health care worker.
• Lack of proper hand washing (or failing to wash at all!) is the greatest cause of nosocomial infections.
• Microorganisms that cause infection and disease are known as pathogens.
• A pathogen is defined as any organism able to inflict harm on the host (person, animal, plant, etc) it infects.
• Pathogens may be bacteria, viruses, protozoans, fungi, or parasitic worms.
• Pathogens are divided into two groups: primary and secondary.
• Primary pathogens can cause disease in a healthy person with a functioning immune system.
• Secondary (or Opportunistic)pathogens usually cause disease in a person with a weakened immune system. The person's immune system may be weak due to stress, poor diet, smoking, dehydration, or the presence of another infection or disease.

• The Chain of Infection includes:  causative agents, reservoirs, portals of exit, means of transmission, portals of entry, and susceptible hosts.
• Think of the steps leading to the development of an infection as being like a chain made of many links.
• If all the links of the chain are present, an infection will occur.
• If even one link can be broken, infection can be prevented.
• As a healthcare worker, you must strive to break the chain of infection.
• You must determine how each link in the chain can be broken.
• Causative agents include: Bacteria, viruses, fungi, protozoa, helminths, and prions.
• Reservoirs include: People, equipment, water, solutions, medications, animals, and soil.
• Portals of exit include: Droplets, excretions, secretions, lesions, wounds, and artificial openings such as catheters, IVs, and drains.
• Means of transmission include: Direct or indirect contact, droplets, airborne, dust, fomites, vehicles, and vectors.
• Portals of entry include: Mucous membranes, breaks in skin, the respiratory tract, the GI tract, the GU tract, and artificial openings such as catheters, IVs, and drains.
• Susceptible hosts include: Immunocompromised, chronic disease, cardiac and/or respiratory disease, diabetics, surgical patients, burns, the elderly, infants and small children.

• The four stages of a disease are:
• Period of Incubation
• Prodromal Period
• AcuteComminicable Period
• Convalescent Period
• The experience of these stages, and the length of each stage, will vary according to the infection.

• Period of Incubation:
• Microorganism gains entry into the host and begins to colonize and infect the patient.
• For a bacterial infection, this is the lag phase of bacterial growth curve.
• Usually no signs or symptoms present.
• With some diseases, a patient is infective (communicable) right from the period of incubation, as soon as the microorganism has entered their body and begun reproducing.

• Prodromal Period:
• Early symptoms begin to appear: perhaps "scratchy" throat, headache, or gastrointestinal discomfort.
• Person feels malaise (mild discomfort).

• Acute/Communicable Period:
• If the disease is communicable, the patient must be kept in isolation to stop the spread of the infection.
• All signs & symptoms of the disease are being displayed.
• Microorganisms are reproducing at an exponential rate.
• Specimen collections are made.
• The body host defenses are in full swing: inflammatory response, antibody production, etc.
• Patient may display fever, rash, and localized symptoms.
• If the antibiotics and other treatments provided are working, plus the patient's immune system is fighting the infection, the patient will begin to experience a decline in symptoms.
• If medical treatments and/or body defenses fail, death will occur.

• Convalescent Period:
• Patient experiences decline of symptoms.
• Often accompanied by a general feeling of weakness, but a sense the "worst" is over.
• Antibody production has reached its peak in the patient.
• The patient's body is repairing itself.

• Terminology of Disease:
• Acute Disease: Lasts a short time and is severe in its symptoms. Ex: flu, colds, measles, chicken pox, or mumps.
• Chronic Disease: Lasts a long time, characterized by a rise and fall of symptoms. Defense mechanisms of the body are unable to respond normally. Often involves hypersensitivity reactions on the part of the body's defenses. Ex: cancer, AIDS, chronic hepatitis, TB, or emphysema.
• Latent Disease: The microorganism is able to "hide out" in the patient's body, remaining inactive for a long period of time, then can become active and infective again. Ex: VZV, or Varicella Zoster Virus. It causes chickenpox, then goes dormant within certain dorsal root ganglia of the spinal cord. It can reactivate in later years as shingles.
• Localized Infection: Small area of the body infected. May only experience gastrointestinal symptoms, or perhaps only respiratory symptoms.
• Systemic, or Generalized, Infection: The infection is able to spread throughout the body via the circulatory or lymphatic systems.
• Symptoms of a Disease: Are the subjective changes in body function "felt" by the patient but not observable to the healthcare worker. Ex: "I feel queasy."
• Signs of a Disease: Are the objective changes that can be observed and measured by the healthcare worker. Ex: fever, rash, swelling, lesions, etc.
• Syndrome: A specific group of symptoms and/or signs always accompanying a particular disease. Ex: Chronic Fatigue Syndrome
• Communicable Disease: Spreads from person-to-person by direct or indirect contact. Ex: chickenpox, measles, TB, genital herpes, etc.

• Virulence is the ability of a bacterium to cause disease.
• Virulence factors are the factors that give the bacterium this ability to cause disease.
• Examples of virulence factors include:
• The ability to adhere to surfaces due to fimbriae and other adhesins.
• Examples of bacteria who use fimbriae for adherence (attachment) are : Moraxella catarrhalis (causes chronic bronchitis) & Neisseria gonorrhoeae (causes gonorrhea).
• The ability to cause nonphagocytic cells of the body to endocytize (engulf) the bacterium.
• Bacteria capable of entering cells by endocytosis include E. coli, species of Shigella, Campylobactor jejuni, species of Salmonella, Neisseria gonorrhoeae , and species of Chlamydia .
• The ability to interfere with phagocytosis by immune system cells, such as macrophages and neutrophils.
• Capsules, protein A, protein G, and certain other enzymes are antiphagocytic.
• Encapsulated Streptococcus pneumoniae causes pneumonia.
• Encapsulated Bacillus anthracis causes anthrax.
• Encapsulated Streptococcus mutans attaches to teeth & causes dental caries.
• Staphylococcus aureus produces protein A which is antiphagocytic.
• Streptococcus pyogenes produces protein G which is antiphagocytic.
• The ability to produce endotoxins.
• When Gram negative bacteria divide or die, the lipid A portion of the LPS layer of their cell wall is released and becomes toxic to the host. It is known as an endotoxin.
• When released, endotoxins bind to macrophages.
• This binding causes the macrophages to release the cytokine known as interleukin-1 (IL-1).
• IL-1 causes the symptoms experienced by the patient, including fever, weakness, and aching. If left untreated, this may result in shock.
• The ability to produce exotoxins.
• Exotoxins are soluble poisonous substances produced and released by living bacterial cells.
• Exotoxins can be produced by many Gram positive and Gram negative bacteria.
• Types of exotoxins include:  A-B Toxins, Cytolytic Toxins, and Superantigens.
• Exotoxins are some of the most potent poisons known to mankind.
• Exotoxins produce the major symptoms and complications of disease.
• The ability to produce protease enzymes which can break down secretory IgA.
• The ability to evade host responses using various means.

• In the clinical (healthcare) setting it is most important that an appropriate specimen be collected from the patient using aseptic technique.
• To determine the organism causing an infection in a patient, a series of tests are run known as C & S Testing (Culture and Sensitivity Testing).
• The "C" stands for the tests run to determine what the organism is.
• The "S" stands for tests which are run to determine the organism's sensitivity and/or resistance to common antibiotics.
• Factors which interfere with collecting viable specimens from patients include:
• If the patient has already started antibiotic therapy, it will be hard to collect a specimen containing sufficient numbers of the pathogen.
• If a patient has a chronic disease or is immunosuppressed, specimen collection will be difficult.
• These are the common Culture Tests ("C" of C & S Testing) employed to determine the identity of a microorganism:
• Microscopic Examination
• Culture (or Biochemical) Testing
• Antigen Testing
• Nucleic Acid and Gene Amplification Testing
• Serological Testing
• These are the common Sensitivity (or Susceptibility) Tests ("S" of C & S Testing) employed to determine the antibiotics of choice:
• Broth Dilution Testing (MIC)
• Disk Diffusion Testing (Kirby-Bauer)
• Beta-Lactamase Testing

Three Methods of Genetic Exchange Between Bacteria:

• Bacteria can exchange genetic material (i.e., some form of DNA) between genera and between species.
• Genetic exchange can occur by these methods: conjugation, transformation, and transduction.
• Whenever a bacterium receives a new portion of DNA, it becomes a new strain of bacteria.

• Conjugation involves either the direct transfer of plasmids from one bacterium to another via a sex pilus or a Hfr cross where a portion of the donor bacterium's chromosome gets transferred to a recipient bacterium.
• Plasmids are small cyclic extrachromosomal DNA molecules composed of 5-100 genes.
• Plasmids replicate independent of the bacterial chromosome. Each bacterial cells contains multiple copies of the plasmid. A bacterium can carry more than one kind of plasmid.
• Plasmids can integrate inside the bacterial cell into its chromosome. When plasmids integrate, the genetic information they code for becomes accessible to the bacterium.
• For example, if the plasmid which integrates carries the genes for resistance to penicillin, the bacterium can now code for those genes (transcription and translation - synthesis of the genetic information). The bacterium now displays resistance to penicillin.
• The F plasmid carries the genetic information for the production of the sex pilus.
• R factor (resistance) plasmids carry genes that code for characteristics such as toxin production (tox gene), antibiotic resistance, production of particular enzymes, or tolerance to heavy metals (nickel, cobalt, and mercury).
• Conjugation has been studied the most in Gram-negative bacteria (such as E. coli and other members of the family Enterobacteriaceae), but is known to occur in Gram-positive bacteria (such as Staphylococcus, Bacillus, Streptomyces, and Enterococcus).
• In an Hfr Cross, chromosomal DNA is transferred from one bacterial cell to another bacterial cell via the sex pilus. This is an additional means by which new strains of bacteria come into existence.
  

• Transduction involves the transfer of bacterial DNA (i.e., parts of the bacterial chromosome) from one bacterium to another bacterium via a bacterial virus. The bacterial virus is known as a bacteriophage, or a phage for short.
• Transduction only occurs when bacterial DNA (part of the chromosome) randomly becomes packaged into a newly formed phage and then is transferred to a new bacterium.
  
• To understand transduction, we must first look at how bacteriophage function:
• Many bacteriophage only undergo a lytic cycle. They infect the host bacterial cell, make multiple copies of themselves (now called virions), then burst (lyse) the host cell to exit.
• Some bacteriophage can also undergo a lysogenic cycle.  Phages which undergo both lytic and lysogenic cycles are called temperate phages.
• Temperate phages infect the host bacterial cell, integrate into the bacterial chromosome (known as a prophage), and "hide out" there for many generations. Each time the bacterium undergoes binary fission, each daughter cell gets a copy of the integrated viral DNA.
• Generalized transduction occurs when some of the virions formed accidentally gain bacterial chromosomal genes (from the host bacterial cell), instead of phage DNA (viral genes). It is called "generalized" because any genes can be transferred. It is a random process.
• When these transduced phages infect new bacterial cells, the bacterial cell gains chromosomal genes from the last host (bacterial) cell.
• If the DNA becomes integrated (lysogenic cycle), the bacterium can now use these genes as if they were their own. They've gained new genetic abilities that used to belong to the other bacterium. They are said to be transduced. Thus, a new strain of bacteria has been created.
• Phage P1 can transduce E. coli genes into Klebsiella and Myxococcus.
• Phage P22 can transduce Salmonella typhimurium genes into other genera.
• In specialized transduction, only a few specific genes are transferred.
• The most studied case of specialized transduction is Lambda phage in E. coli.
• Only temperate phage can undergo specialized transduction.
• To summarize, transduction is random and accidental. It is not the goal of the phage to package bacterial DNA. The phage is actually trying to make new virions (bacteriophage).
• Transduction leads to the formation of new bacterial strains, which have gained bacterial genes from a another bacterium transferred via the bacteriophage (bacterial virus). 

• Certain bacterial diseases only display their symptoms when a bacterium has been infected with a bacteriophage, and that bacteriophage has integrated itself into the bacterium's chromosome. The phage is said to be in its latent state and is called a prophage. The bacterial cell is referred to as a lysogen and is said to have undergone lysogenic conversion.  

• The toxins, which are the virulence factors for these diseases, are only produced when lysogenic conversion has occurred.
• This means that the genes to code for the production of the toxins, known as tox genes, are really phage genes.
• So the disease only occurs when the bacterium itself is infected with the specific phage which codes for the production of the toxin, and the phage has incorporated itself into the bacterium's chromosome, known as the prophage stage.
• Examples of diseases that involve tox genes carried by prophages (i.e., viral DNA intergrated into the bacterial chromosome during lysogenic cycle) include:
• Diphtheria caused by Cornyebacterium diphtheriae
• Botulism caused by Clostridium botulinum
• Scarlet fever caused by Streptococcus pyogenes
• Food poisoning caused by species of Salmonella
  
• Cholera caused by Vibrio chloerae
• Hemolytic Uremic Syndrome (HUS) caused by E. coli O157:H7
  

• Transformation involves the transfer of genetic information by free DNA released from disrupted bacterial cells.
• The source of the free DNA may be by natural release from bacterial during death, or it may be isolated in the laboratory.
• Some genera of bacteria are naturally competent, while other genera can be made artificially competent.
  
• For genera such as Streptococcus, Bacillus, and Haemophilus, transformation appears to be a major means by which genetic transfer occurs. It is also known to occur in genera such as Neisseria, E. coli, and Pseudomonas.

• Besides the three methods of genetic exhange between bacteria, bacterial cells can undergo genetic diversity through the process of transposition. 
• Transposons are DNA segments that can move within a bacterial cell from one plasmid to another plasmid, from a plasmid to the bacterial chromosome, or from the bacterial chromosome to a plasmid.
• Genes for antibiotic resistance, resistance to toxic metals, toxin production, and synthesis of particular enzymes have been found as transposable elements.
• Transposition is known to occur within bacteria, plants, animals, and humans. It is a major force behind genetic diversity.

Anaerobic Bacteria:

• An anaerobic bacterium is one which grows in the absence of oxygen.
• Key points for anaerobic infections:
• Foul odor.
• Mixed infections.
• Abscess formation.
• Endogenous (from the person's own flora).
• The two genera Gram-positive endospore-forming bacteria Bacillus and Clostridium.
• Clostridia are anaerobes.
• Bacilli are aerobes or facultative anaerobes.
• When the endospores enter into a favorable environment, such as the human body, they undergo germination to their natural growing stage, known as the vegetative cells. These grow and reproduce, colonizing and infecting the person.
• Endospores can survive heat, lack of water, antimicrobial agents, chemicals and disinfectants, sunlight, ultraviolet radiation, and boiling.
• Endospores are a survival mechanism. It is not a reproductive process. There is no increase in cell numbers.
• Endospores form within a vegetative cell. One vegetative cell forms one endospore in order to survive, which germinates into one vegetative cells when environmental conditions are again favorable.
• Endospores form by a process called sporulation, also known as sporogenesis.
• Endospores return to vegetative cells by a process called germination.
• Only autoclaving (when done correctly) can kill all endospores.
• When autoclaving is not possible, sporicidal disinfectants should be used to kill endospores. They will kill most, but not all, of the endospores.
• Mixed infections involve anaerobes and facultative anaerobes.
• The facultative anaerobes use up the oxygen, allowing for growth of the anaerobes.
• This often leads to the formation of an abscess.
• An abscess is a localized accumulation of pus in a tissue.
• The pus is a combination of the bacteria growing and reproducing in the area and the response of the immune system cells.
• The bacteria in a mixed infection attempt to "wall themselves off" further removing the oxygen from the area.

• Foodborne intoxication results when a person eats a food product containing an already-produced exotoxin.
• The exotoxin was produced by bacteria living and reproducing in the food product before it was consumed.
• The exotoxin is causing the rapid development of the illness in the person.
• Symptoms can appear within hours of consumption.
• Staphylococcus aureus and Clostridium botulinum produce foodborne intoxication.
• The toxin produced by S. aureus is heat-stable, so is not destroyed by cooking or boiling the food.
• The toxin produced by C. botulinum is heat-labile, so would be destroyed by boiling the food for 15 minutes immediately before consumption.
• Foodborne infection results when a person eats a food product containing living microorganisms.
• Symptoms usually don't appear until after 24 hours of consumption.
• Proper cooking of food will kill microorganisms living in the food, thus preventing infection.
• However, properly cooked food can be contaminated with microorganisms by food preparers after cooking is completed. 
• For foodborne infection by Clostridium perfringes to develop, the patient has to eat food which has been contaminated with the Clostridial organisms. The toxin released acts upon the gastrointestinal system (i.e., as an enterotoxin) causing abdominal pain and diarrhea. It is usually a self-limiting illness, resolving over time without treatment.

• Infant Botulism is becoming the most common form of botulism in the US.
• It affects infants during their first year of life.
• It has been associated with the use of honey, which can contain bacterial endospores of C. botulinum .
• Older children and adults, with fully functioning immune systems, seem to "fight off" the effects of the toxins released by germinating endospores acquired from the honey.
• Immunocompromised persons are also at risk of this infection.

Bacillus anthracis is the cause of Anthrax.

Anthrax is a disease of animals that can spread to humans in close contact with infected animals.

The endospores gain entry through cuts or through mucous membranes.

Human infections occur in workers whose occupations expose them to infected animals (ex: farmers, veterinarians, and slaughter house personnel) or animal products (hides, wook, or hair).

The infection begins as lesions, then spreads through the lymphatic system to the bloodstream.

There are two forms:  pulmonary and cutaneous anthrax.

Penicillin is used for treatment.

5 to 20% of untreated cases result in death.

B. anthracis has been implicated in biological warfare.

• Clinical sites of infection and predisposing condition include:
• Face - poor dental hygiene, dental surgery, or injury.
• Abdomen - surgery or injury.
• Chest - pulmonary infection involving aspiration from the lungs.
• Female genital tract - IUD (intrauterine device).

Most commonly cause intra-abdominal, genital, and pleuropulmonary infections.

• Today, the "golden standard" for achieving sterilization is through autoclaving.
• Sterilization is a process by which we remove all microorganisms, including endospores, from an object. Once treated, the object is considered to be sterile.
• Autoclaving involves the use of moist heat under pressure.
• Typical autoclave settings are 121°C at 15 psi for 15-20 minutes.
• Chemical and biological indicators can be used to ensure the autoclave is working properly.
• A common chemical indicator is specialized tape. It has diagonal marks that will turn black when the correct temperature is reached in the autoclave.
• The most common biological indicator is Bacillus stearothermophilus , which produces heat-resistant spores. After autoclaving, the endospores are mixed with growth media and placed in an incubator. If the endospores were not killed during the autoclave process, they will germinate. This would mean the autoclave wasn't working! So lack of growth is the hoped for result!
  

Actinomycosis (or Lumpy Jaw):

• Actinomyces israelii is responsible for antinomycosis.
• A. isralelii is a Gram positive, non-sporing, filamentous, branching, anaerobic bacterium.
• A. isralelii inhabits the mouth and gingiva.
• Actinomycosis is slowly progressive. There can be painful swellings (abscesses) under the skin, in the area of the jaw or neck, that eventually open and drain. The sores may heal, reappear, and drain for weeks, creating cycles of abscess formation and scarring.
• Many cases follow dental surgery.
• Penicillin and tetracycline are used to treat, and must be administered for extended periods, because the bacteria are so slow-growing.
• Proper care must be taken following surgery, especially dental/oral surgery, to prevent this disease.

• Clostridium botulinum is responsible for the disease botulism. Most botulism is foodborne. However, there is also wound botulism and infant botulism.
• Foodborne Botulism does not occur frequently in the United States. When it does, it is usually associated with home-canned or home-processed foods such as vegetables, fish, meats, or potato salad.
• The endospores of C. botulinum were within the food when it was processed. Due to poor processing, they were not destroyed. They were allowed to germinate into vegetative cells.
• Botulism involves the production of a powerful neurotoxin by the vegetative cells. The neurotoxin has already been produced in the contaminated food, and is ingested along with the food. Therefore, this disease is referred to as foodborne intoxication (the toxin was eaten).
• Symptoms begin within 12-36 hours after ingestion.
• This neurotoxin binds to nerve endings blocking the release of acetylcholine, the neurotransmitter present at neuromuscular junctions.
• Intestinal symptoms occur first, and become quite severe. If left untreated, vital muscles of the circulatory and respiratory systems stop functioning, leading to the death of the individual.
• Boiling foods at 100 C for at least 10 minutes will inactivate the neurotoxin.
• The best prevention is to check foods thoroughly for possible contamination (bulging cans, unusual surface film, etc).
• Do not taste foods to determine if they are contaminated! The amount of food ingested from a licked spoon has been enough to cause serious illness!
• Treatment involves the use of preformed antitoxin, which is a special form of antibody against the neurotoxin, along with supportive therapy.
• There are no vaccines available against botulism.

• Clostridium perfringes is responsible for the disease gas gangrene, plus it can cause a form of food poisoning.
• Gas Gangrene (or Clostridial Myonecrosis) is associated with surgical wounds, injury, and severe burns.
• Persons with poor cardiovascular or pulmonary function, such as diabetics, are at greatest risk.
• There has to be an opening by which the endospores enter the person's body. Within the person's body, an anaerobic (or low oxygen) environment must be present in order for germination to occur.
• Symptoms usually appear within one to four days. There is severe pain at the site of the injury and the wound displays gaseous, discolored, and often smelly tissue destruction.
• Treatment involves debridement of the wound, antibiotics, supportive therapy, and the use of hyperbaric oxygen.
• If necessary, an infected limb will have to be removed. This disease usually affects limbs (preferably legs) due to the poor circulation in the peripheral system.
• There are no vaccines or antitoxins available.

• Clostridium difficile is responsible for two forms of colitis known as Pseudomembranous Colitis and AAC (Antibiotic-Associated Colitis).
• This organism is found as normal fecal flora in 3% of healthy persons.
• It is an increasing problem in nursing homes and long-term care facilities.
• It is estimated that 10 - 30% of hospitalized individuals are colonized by C. difficile , plus 60 - 70% of newborns.
• C. difficile has been isolated from the hands of health care workers caring for patients colonized with the bacterium.
• The endospores can survive on fomites and surfaces for several months.
• Since common disinfectants used for daily cleaning are not sporicidal (capable of killing endospores), the endospores survive the cleaning process and are found in high numbers in the rooms of patients colonized or infected with C. difficile  
• This organism can contaminate feeding tubes, catheters, and instruments used by such patients.
• Because of this health care workers are supposed to employ contact precautions, along with all standard precautions, around such patients.
• Since episodes of AAC are triggered by a particular antibiotic that was being used by the patient in therapy, it requires permanent discontinuation of the offending antibiotic along with supportive therapy.
• Further antibiotic therapy is considered unnecessary in patients with only mild symptoms. The diarrhea usually clears up in 7 to 10 days.
• When needed, the antibiotics most frequently used for treatment are vancomycin, metronidazole, bacitracin, and rifampin.
• There are no vaccines or antitoxins available.

• Clostridium tetani is responsible for the disease Tetanus.
• The bacterial endospore gains entry through cuts, scrapes, injury, and wounds. Once inside the body, the spores germinate.
• C. tetani produces a powerful neurotoxin which is absorbed into peripheral axons and carried to target neurons in the spinal column.
• The toxin attaches to junctions of regulatory neurons. Muscles receive constant stimulaiton and contract uncontrollably. The result is spastic paralysis.
• Symptoms usually appear 3 to 21 days after the injury. Symptoms progress from inability to use the muscles of the neck and jaw (known as lockjaw), to difficulty with respiratory and cardiac function.
• There is a vaccination available to prevent tetanus. It consists of a series of four DTaP shots given at 2 months, 4 months, 6 months, and the fourth shot given between 12 - 18 months of age.
• A DTaP booster shot is to be given between 4 - 6 years of age.
• A Td shot is given at 11-12 years.
  
• From that point on, Td boosters are recommended every 10 years.
• However, if a person has a severe injury where tetanal endospores are suspected to have contaminated the wound, then a booster shot will be given even sooner.
• Antitoxins may also be administered to the patient as a preventative measure.

Anaerobic Bacterial Diseases:

• There are six anaerobic bacterial infections/diseases  we will concentrate on in this course. These diseases were NOT assigned as part of a group activity.  You were to complete the information on these five diseases yourself!
• For each disease you must know the following:  1) name of disease, 2) causative agent(s) and its description, 3) symptoms, 4) incubation period, 5) pathogenesis, 6) epidemiology, 7) treatment (Note: Be specific!), 8) prevention, 9) control, and 10) isolation precautions employed in a healthcare setting for the disease (including information contained in footnotes).

• Actinomycosis (or Lumpy Jaw)
• Foodborne Botulism 
• Clostridial Myonecrosis (or Gas Gangrene)
• Pseudomembraneous Colitis (or Antibiotic-Associated Colitis)
• Infections caused by Bacteroides fragilis and Other AGNB (Anaerobic Gram Negative Bacteria)
  
• Tetanus (or Lockjaw)
• Note: You must discuss the tetanus vaccination schedule (number of shots & when given) for children, adolescents, and adults. Distinguish between when DTaP is used and Td is used.
  

Isolation Precautions:

• The link to the Isolation Precautions Guideline: http://www.cdc.gov/ncidod/hip/isolat/isolat.htm
• In the health care field, we refer to measures employed to protect yourself and your patients as isolation precautions. Since the need for such precautions was first recognized in 1877, a series of precaution guidelines have evolved.
• To assist hospitals in maintaining up-to-date isolation practices, the Centers for Disease Control and Prevention (CDC) and the Hospital Infection Control Practices Advisory Committee (1) (HICPAC) have revised the "CDC Guideline for Isolation Precautions in Hospitals."
• HICPAC was established in 1991 to provide advice and guidance to the Secretary, Department of Health and Human Services (DHHS); the Assistant Secretary for Health, DHHS; the Director, CDC; and the Director, National Center for Infectious Diseases, regarding the practice of hospital infection control and strategies for surveillance, prevention, and control of nosocomial infections in US hospitals. HICPAC also advises the CDC on periodic updating of guidelines and other policy statements regarding prevention of nosocomial infections.

• In 1985, largely because of the HIV epidemic, Universal Precautions (UP) were developed for all health care workers. These guidelines emphasized applying blood and body fluid precautions universally to all persons regardless of their infection status. UP were updated in 1987 and 1988.

• Universal Precautions included:
• All health care workers should use barrier precautions to prevent skin and mucous membrane exposure when contact is anticipated with blood, semen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, amniotic fluid, or any body fluid containing visible blood.
• Barrier protection should also be used for handling items and/or surfaces soiled with blood or body fulids.
• Gloves should be worn for venipuncture and for touching blood and body fluids, mucous membranes, or nonintact skin.
• Masks, owns, and protective eyewear should be worn for procedures likkely to generate droplets, splashes, or sparys of blood or body fluids.
• Gloves should be changed after contact with each patient. Gloves should not be washed or reused. Hands should be washed immediately after gloves are removed.
• Precautions should be used to prevent injuries when using , cleaning, or disposing of needles, scalpels, and other sharp instruments or devices. These should be placed in puncture-resistant contianers for disposal.
• Resuscitation bags should be available to avoid mouth-to-mouth contact.
• Health care workers with open lesions should not be involved in direct patient care or handling patient-care equipment.

• In 1987, Body Substance Isolation (BSI) guidelines were proposed.
• BSI emphasized isolation of all moist and potentially infectious body substances from all patients, primarily through the use of gloves.
• In BSI, signs are placed on the doors of patients with airborne infections, referring visitors to the floor nurse before entering.
• BSI stressed the application of fresh gloves before contact with moist body substances.
• It did not emphasize hand washing after removal of gloves, unless the hands were visibly soiled because of glove punctures.

• In 1991, OSHA’s final rule of the Bloodborne Pathogens Standard was published. It emphasized universal precautions.

• By the 1990s many healthcare workers were uncertain about which guidelines to follow!
• Besides Universal Precautions, other guidelines for infection control being practiced included Body Substance Isolation, Blood and Body Fluid Precautions, Category-Specific Isolation, and Disease-Specific Isolation. Most health care settings were using a mixed combination of all the guidelines, referring to them as universal precautions.
• As a result, the Standard and Transmission-Based Precautions were agreed upon by the CDC, HICPAC, Public Health Service, and U.S. Department of Health and Human Services.
• These came out in draft form in 1994 and final form in 1996.

• There are five main routes of transmission: contact, droplet, airborne, common vehicle, and vectorborne.
• Contact transmission is the most important and frequent mode of transmission of nosocomial infections. It is divided into two subgroups:
• Direct-contact transmission involves a direct body surface to body surface contact and physical transfer of microorganisms between a susceptible host and an infected or colonized person, such as occurs when a person turns a patient, gives a patient a bath, or performs other patient-care activities that require direct personal contact.
• Direct-contact transmission also can occur between two patients, with one serving as the source of the infectious microorganisms and the other as a susceptible host.
• Indirect-contact transmission involves contact of a susceptible host with a contaminated intermediate object, usually inanimate, such as contaminated instruments, needles, or dressings, or contaminated hands that are not washed and gloves that are not changed between patients.
• Droplet transmission involves the formation of droplets, which are generated from the source person primarily during coughing, sneezing, and talking, and during the performance of certain procedures such as suctioning and bronchoscopy.
• Transmission occurs when droplets containing microorganisms generated from the infected person are propelled a short distance through the air and deposited on the host's conjunctivae, nasal mucosa, or mouth.
• Because droplets do not remain suspended in the air, special air handling and ventilation are not required to prevent droplet transmission; that is, droplet transmission must not be confused with airborne transmission.
• Airborne transmission occurs by dissemination of either airborne droplet nuclei (small-particle residue, 5 µm or smaller in size, of evaporated droplets containing microorganisms that remain suspended in the air for long periods of time) or dust particles containing the infectious agent.
• Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by a susceptible host within the same room or over a longer distance from the source patient, depending on environmental factors.
• Special air handling and ventilation are required to prevent airborne transmission.
• Microorganisms transmitted by airborne transmission include Mycobacterium tuberculosis, the Rubeola virus, and the Varicella virus.
• Common vehicle transmission applies to microorganisms transmitted by contaminated items such as food, water, medications, devices, and equipment.
• Vectorborne transmission occurs when vectors such as mosquitoes, flies, rats, and other vermin transmit microorganisms.
• This route of transmission is of less significance in hospitals in the United States than in other regions of the world.

• You are to apply Standard Precautions as a healthcare worker:

• Each and every time you work with a patient.
• Apply  to blood.
• Apply to all body fluids, secretions, and excretions except sweat, regardless of whether or not they contain visible blood. Body fluids include urine, feces, pus, saliva, spit, tears, mucus, vomit, sputum, vaginal or penal secretions, afterbirth and any other fluid-like substance which could come from a patient.
• Apply to nonintact skin.
• Apply to mucous membranes.
• Standard Precautions are designed to reduce the risk of transmission of microorganisms from both recognized and unrecognized sources of infection and are meant to bring about the control of infections.
• An obvious time you will be exposed directly to bodily fluids is during specimen collection. Therefore, as you learn to collect specimens in the lab you will learn how to employ isolation precautions.

• Handwashing:
• Handwashing is the single most important measure to reduce the risks of transmitting organisms from one person to another or from one site to another on the same patient.
• Wash hands after touching blood, body fluids, secretions, excretions, and contaminated items, regardless of whether gloves were worn.
• Wash hands (1) immediately after removing gloves, (2) between patient contacts (i.e., as you move from one patient to your next patient), and (3) whenever it would be wise and prudent.
• Wash hands between tasks and procedures on the same patient to prevent cross contamination of different body sites.
• Use a plain (nonantimicrobial) soap for routine handwashing.
• Use an antimicrobial agent or a waterless antiseptic agent for specific circumstances.

• Use of Clean, Nonsterile Gloves:
• Gloves are worn to provide a protective barrier and to prevent gross contamination of the hands when touching blood, body fluids, secretions, excretions, mucous membranes, and nonintact skin.
• The wearing of gloves in specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the OSHA bloodborne pathogens final rule.
• Gloves are worn to reduce the likelihood that microorganisms present on the hands of personnel will be transmitted to patients during invasive or other patient-care procedures that involve touching a patient's mucous membranes and nonintact skin.
• Gloves are worn to reduce the likelihood that hands of personnel contaminated with microorganisms from a patient or a fomite can transmit these microorganisms to another patient.
• In this situation, gloves must be changed between patient contacts and hands washed after gloves are removed.
• Wear clean, nonsterile gloves when touching blood, body fluids, secretions, excretions, and contaminated items.
• Put on clean gloves just before touching mucous membranes and nonintact skin.
• Change gloves between tasks and procedures on the same patient to prevent cross contamination of different body sites.
• Remove gloves (1) promptly after use, (2) before touching noncontaminated items and environmental surfaces, and (3) before going to another patient.
• Wash hands immediately after removing gloves.
• Wearing gloves does not replace the need for handwashing, because gloves may have small, inapparent defects or may be torn during use, and hands can become contaminated during removal of gloves.

• Use of Clean, Nonsterile Masks, Eye Protection, Face Shields:
• Wear a mask  that covers both the nose and the mouth, eye protection (goggles or safety glasses), or a face shield to protect mucous membranes of the eyes, nose, and mouth during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, and excretions.
• The wearing of masks, eye protection, and face shields in specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the OSHA bloodborne pathogens final rule.
• A surgical mask is worn to prevent droplet transmission.
• It provides protection against spread of large-particle droplets that are transmitted by close contact and generally travel only short distances (up to 3 ft) from infected patients who are coughing or sneezing.

• Use of Clean, Nonsterile Gowns and Protective Apparel:
• Wear a clean, nonsterile gown whenever the likelihood of splashes or sprays of blood, body fluids, secretions, and excretions exists.
• The type of gown worn should be appropriate for the activity.
• Wear a clean, nonsterile gown during procedures that will cause soiling of clothing.
• Remove a soiled gown as soon as possible and wash hands.
• Gowns especially treated to make them impermeable to liquids, leg coverings, boots, or shoe covers provide greater protection to the skin when splashes or large quantities of infective material are present or anticipated.
• The wearing of gowns and protective apparel under specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the OSHA bloodborne pathogens final rule.
• Gowns are also worn by personnel during the care of patients infected with epidemiologically important microorganisms (such as MRSA, VRE, VISA, and VRSA) to reduce the opportunity for transmission of pathogens from patients or items in their environment to other patients or environments.
• When gowns are worn for this purpose, they are removed before leaving the patient's environment and hands are washed.

• Patient-Care Equipment and Articles:
• Handle equipment soiled with blood, body fluids, secretions, and excretions in a manner that prevents contamination to yourself, other patients, and environmental surfaces.
• Contaminated, reusable critical medical devices or patient-care equipment (i.e., equipment that enters normally sterile tissue or through which blood flows) are sterilized after use to reduce the risk of transmission of microorganisms to other patients.
• Contaminated, reusable semicritical medical devices or patient-care equipment (i.e., equipment that touches mucous membranes) are sterilized or disinfected (reprocessed) after use to reduce the risk of transmission of microorganisms to other patients.
• The type of reprocessing is determined by the article and its intended use, the manufacturer's recommendations, hospital policy, and any applicable guidelines and regulations.
• Contaminated, reusable noncritical equipment (i.e., equipment that touches intact skin) is cleaned and disinfected after use, according to hospital policy.
• Contaminated disposable (single-use) patient-care equipment is handled and transported in a manner that reduces the risk of transmission of microorganisms and decreases environmental contamination in the hospital.
• The equipment is disposed of according to hospital policy and applicable regulations.

• Environmental Control:
• There must be adequate procedures for the routine care, cleaning, and disinfection of environmental surfaces and equipment.
• Routine cleaning: The day-to-day cleaning of a room while a patient is there.
• The room, or cubicle, and bedside equipment of patients on Transmission-Based Precautions are cleaned using the same procedures used for patients on Standard Precautions, unless the infecting microorganism(s) and the amount of environmental contamination indicates special cleaning.
• The methods, thoroughness, and frequency of cleaning and the products used are determined by hospital policy.
• In addition to thorough routine cleaning, adequate disinfection of bedside equipment and environmental surfaces (e.g., bedrails, bedside tables, carts, commodes, doorknobs, faucet handles) is indicated for certain pathogens, especially Enterococci , which can survive in the inanimate environment for prolonged periods of time.
• The process of cleaning after the patient leaves is known as terminal cleaning.
• Patients admitted to hospital rooms that previously were occupied by patients infected or colonized with infectious pathogens are at increased risk of infection from contaminated environmental surfaces and bedside equipment if they have not been cleaned and disinfected adequately.
• No special precautions are needed for dishes, glasses, cups, or eating utensils.
• Either disposable or reusable dishes and utensils can be used for patients on isolation precautions.
• The combination of hot water and detergents used in hospital dishwashers is sufficient to decontaminate dishes, glasses, cups, and eating utensils.

• Linen and Laundry:

• Although soiled linen may be contaminated with pathogenic microorganisms, the risk of disease transmission is negligible if it is handled, transported, and laundered in a manner that avoids transfer of microorganisms to patients, personnel, and environments.
• Rather than rigid rules and regulations, hygienic and common sense storage and processing of clean and soiled linen are recommended.
• The methods for handling, transporting, and laundering of soiled linen are determined by hospital policy and any applicable regulations.
• Used linen (bed sheets, blankets, towels, bibs, diapers, etc) must be handled, transported, and processed in a manner that prevents contamination to yourself, other patients, and environmental surfaces.

• Occupational Health and Bloodborne Pathogens:

• Care must be taken with needles, scalpels, and all sharp instruments or devices to prevent injuries.
• Never recap needles.
• Never use techniques which would direct the point of a needle toward any part of your body.
• Place used disposable syringes and needles, scalpel blades, and other sharps in puncture-resistant containers located as close as practical to the area of use.
• Place reusable syringes in puncture-resistant containers for transport.
• Use mouthpieces, resuscitation bags, or other ventilation devices as an alternative to mouth-to-mouth resuscitation.

• Patient Placement:

• A private room is used to prevent direct- or indirect-contact transmission when the source patient has poor hygienic habits, contaminates the environment, or cannot be expected to assist in maintaining infection control precautions to limit transmission of microorganisms (i.e., infants, children, and patients with altered mental status).
• When possible, a patient with highly transmissible or epidemiologically important microorganisms (such as MRSA, VRE, VISA, and VRSA) is placed in a private room with handwashing and toilet facilities, to reduce opportunities for transmission of microorganisms.
• When a private room is not available, an infected patient is placed with an appropriate roommate.
• Sharing of rooms, referred to as cohorting patients, is useful especially during outbreaks.
• Patients infected by the same microorganism usually can share a room, provided they are not infected with other potentially transmissible microorganisms and the likelihood of reinfection with the same organism is minimal.
• When an infected patient shares a room with a noninfected patient, it is important that patients, personnel, and visitors take precautions to prevent the spread of infection and that roommates are selected carefully.
• A private room with appropriate air handling and ventilation is important for reducing the risk of transmission of microorganisms spread by airborne transmission.
• Some hospitals use an isolation room with an anteroom as an extra measure of precaution to prevent airborne transmission.

• Transport of Infected Patients:

• Limiting the movement and transport of patients infected with virulent or epidemiologically important microorganisms reduces opportunities for transmission of microorganisms in hospitals.
• When transport of infected patients is necessary:
• Appropriate barriers (e.g., masks, impervious dressings) must be used by the patient to reduce the opportunity for transmission of pertinent microorganisms to other patients, personnel, and visitors and to reduce contamination of the environment.
• Personnel in the area to which the patient is to be taken should be notified of the impending arrival of the patient and of the precautions to be used to reduce the risk of transmission of infectious microorganisms.
• Patients should be informed of ways by which they can assist in preventing the transmission of their infectious microorganisms to others.

• Transmission-Based Precautions apply to patients known or suspected to be infected with (1) a pathogen which is highly transmissible, and (2) an epidemiologically important pathogen, such as a multidrug-resistant microorganism.
• Transmission-Based Precautions are used in addition to Standard Precautions.
• This means you employ all Standard Precautions, plus the additional precautions which relate to the situation.
• There are three types of Transmission-Based Precautions: (1) airborne, (2) droplet, and (3) contact.

• Are used in addition to Standard Precautions for patients known or suspected to have serious illnesses transmitted by airborne droplet nuclei, such as tuberculosis, measles, and chickenpox. Small, infective particles (less than 5 µm in size) can be free floating or combined with dust particles in the air.

• Patient Placement:
• The patient is to be placed in a private room that has (1) monitored negative air pressure, (2) six to twelve air changes per hour, and (3) appropriate discharge of the air to the outdoors or monitored filtration of the air before it is circulated (i.e., HEPA or high-efficiency particulate air filter).
• The door to the room must be kept closed.
• If cohorting (sharing a room) is necessary, patients with an active infection caused by the same microorganism and no other infections may be placed together.
• Respiratory Protection:
• Approved respiratory masks are to be worn in patient's room whenever airborne precautions are in place.
• HEPA and N95 (N category at 95% efficiency) filter respirators meet the CDC performance criteria for tuberculosis respirators.
• Susceptible workers should not enter the room of patients with known or suspected measles or chickenpox if other workers are available.
• If no other workers are available, susceptible workers are to wear approved respiratory masks.
• Persons immune to measles or chickenpox need not wear such masks.
• Patient Transport:
• The transport of such patients is only for essential purposes.
• Patients should wear a surgical mask to prevent dispersal of droplet nuclei.
• Tuberculosis:
• When tuberculosis is suspected or confirmed, follow CDC Guidelines for Preventing the Transmission of Tuberculosis in Health-Care Facilities.

• Are used in addition to Standard Precautions for patients known or suspected to have serious illnesses transmitted by large-particle droplets, greater than5 µm in size, which can be spread by coughing, sneezing, or talking.
• Diseases fitting this category include: invasive Haemophilus influenzae type b (causing meningitis, pneumonia, epiglottitis, and sepsis), invasive Neisseria meningitidis (causing meningitis, pneumonia, and sepsis), diphtheria, Mycoplasma pneumonia, pertussis, pneumonic plague, streptococcal infections (pharyngitis, pneumonia, or scarlet fever), adenovirus, influenza, mumps, parvo virus B19, and rubella.

• Patient Placement:
• The patient is to be placed in a private room.
• If cohorting is necessary, patients with an active infection caused by the same microorganism and no other infections may be placed together.
• If private rooms or cohorting are not available options, patients must be separated by at least 3 feet from other patients or visitors. (This is known as the 3-foot rule.)
• Mask:
• A mask must be worn when working within 3 feet of the patient.
• Patient Transport:
The transport of such patients is only for essential purposes.
Patients should wear a surgical mask to prevent dispersal of large-particle droplets.

• Are used in addition to Standard Precautions for patients known or suspected to have serious illnesses transmitted by direct patient contact or by contact with patient-care equipment and articles.
• These illnesses include:
• Multidrug resistant bacteria causing GI, respiratory, skin, or wound infections
• Enteric infections involving Clostridium difficile, E. coli O157:H7, Shigella, Salmonella, Hepatitis A, Hepatitis E, Rotavirus, Giardia lamblia, and all other gastroenteral infections which are passed fecal-oral. You will apply contact precautions for all diapered or incontinent patients, irregardless of their age.
• RSV (respiratory syncytial virus)
• Viral hemorrhagic conjunctivitis
• Viral hemorrhagic infections (Ebola, Lassa, or Marburg)
• Skin infections involving cutaneous diphtheria, herpes simplex virus, impetigo, major abscesses or cellulitis, pediculosis, scabies, staphylococcal furunculosis, and disseminated zoster.

• Patient Placement:
• The patient is to be placed in a private room.
• If cohorting is necessary, patients with an active infection caused by the same microorganism and no other infections may be placed together.
• Gloves and Hand Washing:
• Wear gloves when entering the room.
• Change gloves after having contact with infective material.
• Remove gloves before leaving the patient's room and wash hands with an antimicrobial agent or a water less antiseptic agent.
• After washing, be certain not to recontaminate hands.
• Gown:
• Wear a gown when entering the room.
• Remove gown before leaving the patient's room. After removing, be certain not to contaminate your clothing.
• Patient Transport:
• The transport of such patients is only for essential purposes.
• Take precautions to prevent transmission to other patients, environmental surfaces, and equipment.
• Patient-Care Equipment:
• As much as possible, use equipment with a single patient or cohorted patients.
• Equipment must be thoroughly cleaned and disinfected before being used with another patient.
• There are additional guidelines to be followed when dealing with such drug-resistant organisms as MRSA (methicillin-resistant Staphylococcus aureus ) and VRE (vancomycin-resistant Enterococcus).

Types of Hand Hygiene:

• Hand hygiene is a general term that applies to either (1) handwashing, (2) antiseptic handwash, (3) antiseptic hand rub, or (4) surgical hand antisepsis. In other words, it includes either handwashing or some form of hand antisepsis.

• Handwashing is washing hands with plain (non-antimicrobial) soap and water.
• Hand antisepsis is a general term that refers to either antiseptic handwash or antiseptic hand rub. In other words, use of an antiseptic (antimicrobial) agent in one form or another .

• Antiseptic agent is an antimicrobial substances that are applied to the skin to reduce the number of microbial flora. Examples include alcohols, chlorhexidine, chlorine, hexachlorophene, iodine, chloroxylenol (PCMX), quaternary ammonium compounds, and triclosan. Triclosan is the main ingredient used in antimicrobial soaps.

•  Antiseptic handwash is washing hands with water and antimicrobial soap or other detergents containing an antiseptic agent. 
• Antimicrobial soap is a soap (i.e., detergent) containing an antiseptic agent, usually 0.2-2% triclosan.
  
• So if you use an antimicrobial soap at home, you're not just washing your hands, you're performing an antiseptic handwash!
  
• Antiseptic hand rub means applying an antiseptic hand-rub product to all surfaces of the hands to reduce the number of microorganisms present.
• Alcohol-based hand rub is an example of an antiseptic hand rub. 
• It is an alcohol-containing preparation designed for application to the hands for reducing the number of viable microorganisms on the hands. 
• In the United States, such preparations usually contain 60%--95% ethanol or isopropanol.

Transmission of health-care-associated pathogens from one patient to another via the hands of HCWs requires the following sequence of events:

• Organisms present on the patient's skin, or that have been shed onto inanimate objects in close proximity to the patient, must be transferred to the hands of HCWs.
• These organisms must then be capable of surviving for at least several minutes on the hands of personnel.
• Handwashing or hand antisepsis by the worker must be inadequate or omitted entirely, or the agent used for hand hygiene must be inappropriate.
• The contaminated hands of the caregiver must come in direct contact with another patient, or with an inanimate object that will come into direct contact with the patient.

Shortcomings of Traditional Testing Methods:

• Accepted methods of evaluating hand-hygiene products intended for use by HCWs require that test volunteers wash their hands with a plain or antimicrobial soap for 30 seconds or 1 minute, despite the observation in the majority of studies that the average duration of handwashing by hospital personnel is actually <15 seconds.
• Methods for evaluating waterless antiseptic agents for use as antiseptic hand rubs require that 3 mL of alcohol be rubbed into the hands for 30 seconds, followed by a repeat application for the same duration. This method does not reflect actual usage patterns among HCWs.

Review of Preparations Used for Hand Hygiene:

• Plain (Non-Antimicrobial) Soap

• Soaps are detergent-based products that contain esterified fatty acids and sodium or potassium hydroxide.
•  They are available in various forms including bar soap, tissue, leaflet, and liquid preparations. 
• Their cleaning activity can be attributed to their detergent properties, which result in removal of dirt, soil, and various organic substances from the hands. 
• Plain soaps have minimal, if any, antimicrobial activity. 
• Handwashing with plain soap can remove loosely adherent transient flora.

• Alcohols

  • The majority of alcohol-based hand antiseptics contain either isopropanol, ethanol, n-propanol, or a combination of two of these products. 
  • The antimicrobial activity of alcohols can be attributed to their ability to denature proteins. 
  • Alcohol solutions containing 60%--95% alcohol are most effective, and higher concentrations are less potent because proteins are not denatured easily in the absence of water. 
  • Alcohols have excellent in vitro germicidal activity against gram-positive and gram-negative vegetative bacteria, including multidrug-resistant pathogens (e.g., MRSA and VRE), Mycobacterium tuberculosis ,and various fungi . 
• Certain enveloped (lipophilic) viruses (e.g., herpes simplex virus, human immunodeficiency virus [HIV], influenza virus, respiratory syncytial virus, and vaccinia virus) are susceptible to alcohols when tested in vitro. 
• Hepatitis B virus is an enveloped virus that is somewhat less susceptible but is killed by 60%--70% alcohol,
• Hepatitis C virus is killed by 60%--70% alcohol. 
• Alcohols, when used in concentrations present in alcohol-based hand rubs, have in vivo activity against three nonenveloped viruses: rotavirus, adenovirus, and rhinovirus.
• Alcohols have poor activity against bacterial spores, protozoan oocysts, and certain nonenveloped (nonlipophilic) viruses.
  
• Alcohols are not appropriate for use when hands are visibly dirty or contaminated with proteinaceous materials.
• The effectiveness of alcohol-based hand-hygiene products is determined by several factors:
• The type of alcohol used
• Concentration of alcohol
• Contact time
• Volume of alcohol used
• Whether the hands are wet when the alcohol is applied
• Frequent use of alcohol-based formulations for hand antisepsis can cause drying of the skin unless emollients, humectants, or other skin-conditioning agents are added to the formulations.
• Alcohols are both flammable and volatile.
  

• Chlorhexidine

• Chlorhexidine gluconate is a cationic bisbiguanide. 
• The antimicrobial activity of chlorhexidine is likely attributable to attachment to, and subsequent disruption of, cytoplasmic membranes, resulting in precipitation of cellular contents. 
• Chlorhexidine has good activity against gram-positive bacteria, less activity against gram-negative bacteria and fungi, and only minimal activity against tubercle bacilli. 
• Chlorhexidine is not sporicidal. 
• It has in vitro activity against enveloped viruses (e.g., herpes simplex virus, HIV, cytomegalovirus, influenza, and RSV) but substantially less activity against nonenveloped viruses (e.g., rotavirus, adenovirus, and enteroviruses).
• Addition of low concentrations (0.5%--1.0%) of chlorhexidine to alcohol-based preparations results in greater residual activity than alcohol alone.

• Hexachlorophene

• Hexachlorophene is a bisphenol composed of two phenolic groups and three chlorine moieties. 
• The antimicrobial activity of hexachlorophene results from its ability to inactivate essential enzyme systems in microorganisms. 
• Hexachlorophene is bacteriostatic, with good activity against S. aureus and relatively weak activity against gram-negative bacteria, fungi, and mycobacteria.
• In the early 1970s, certain infants bathed with hexachlorophene developed neurotoxicity. As a result, in 1972, the FDA warned that hexachlorophene should no longer be used routinely for bathing infants. Current guidelines still recommend against the routine bathing of neonates with hexachlorophene because of its potential neurotoxic effects.
• Hexachlorophene  is classified by FDA TFM as not generally recognized as safe and effective for use as an antiseptic handwash. 
• Hexachlorophene should not be used to bathe patients with burns or extensive areas of susceptible, sensitive skin. 
• Soaps containing 3% hexachlorophene are available by prescription only.
  

• Iodine and Iodophors

• Iodine has been recognized as an effective antiseptic since the 1800s. Because iodine often causes irritation and discoloring of skin, iodophors have largely replaced iodine as the active ingredient in antiseptics.
• Iodine molecules rapidly penetrate the cell wall of microorganisms and inactivate cells by forming complexes with amino acids and unsaturated fatty acids, resulting in impaired protein synthesis and alteration of cell membranes.
• Iodophors are composed of elemental iodine, iodide or triiodide, and a polymer carrier (i.e., the complexing agent) of high molecular weight. 
• The amount of molecular iodine present (so-called "free" iodine) determines the level of antimicrobial activity of iodophors. 
• "Available" iodine refers to the total amount of iodine that can be titrated with sodium thiosulfate. Typical 10% povidone-iodine formulations contain 1% available iodine and yield free iodine concentrations of 1 ppm. 
• The antimicrobial activity of iodophors also can be affected by pH, temperature, exposure time, concentration of total available iodine, and the amount and type of organic and inorganic compounds present (e.g., alcohols and detergents).
• Iodine and iodophors have bactericidal activity against gram-positive, gram-negative, and certain spore-forming bacteria (e.g., clostridia and Bacillus spp.) and are active against mycobacteria, viruses, and fungi. 
• In concentrations used in antiseptics, iodophors are not sporicidal. 
• Povidone-iodine 5%--10% has been tentatively classified by FDA TFM as a Category I agent (i.e., a safe and effective agent for use as an antiseptic handwash and an HCW handwash). 
• The majority of iodophor preparations used for hand hygiene contain 7.5%--10% povidone-iodine.

• Quaternary Ammonium Compounds

• Quaternary ammonium compounds are composed of a nitrogen atom linked directly to four alkyl groups.
• Alkyl benzalkonium chlorides are the most widely used as antiseptics. 
• Other compounds that have been used as antiseptics include benzethonium chloride, cetrimide, and cetylpyridium chloride. 
• The antimicrobial activity of this group of compounds involves adsorption to the cytoplasmic membrane, with subsequent leakage of low molecular weight cytoplasmic constituents.
• Quaternary ammonium compounds are primarily bacteriostatic and fungistatic.
• They are more active against gram-positive bacteria than against gram-negative bacilli. 
• Quaternary ammonium compounds have relatively weak activity against mycobacteria and fungi and have greater activity against lipophilic viruses.
• Because of weak activity against gram-negative bacteria, benzalkonium chloride is prone to contamination by these organisms. Several outbreaks of infection or pseudoinfection have been traced to quaternary ammonium compounds contaminated with gram-negative bacilli.
  

• Triclosan

• Triclosan (chemical name: 2,4,4'-trichloro-2'-hydroxy-diphenyl ether) is a nonionic, colorless substance. 
• It has been incorporated into soaps for use by HCWs and the public and into other consumer products. 
• Concentrations of 0.2%--2% have antimicrobial activity. 
• Triclosan enters bacterial cells and affects the cytoplasmic membrane and synthesis of RNA, fatty acids, and proteins.

• The widespread prevalence of healthcare-associated diarrhea caused by Clostridium difficile, and the recent occurrence in the United States of human Bacillus anthracis infections associated with contaminated items sent through the mail, has raised concern regarding the activity of antiseptic agents against spore-forming bacteria. 
• None of the agents (including alcohols, chlorhexidine, hexachlorophene, iodophors, PCMX, and triclosan) used in antiseptic handwash or antiseptic hand-rub preparations are reliably sporicidal against Clostridium spp. or Bacillus spp. 
• Washing hands with non-antimicrobial or antimicrobial soap and water may help to physically remove spores from the surface of contaminated hands. 
• HCWs should be encouraged to wear gloves when caring for patients with C. difficile-associated diarrhea.

Fingernails and Artificial Nails:

• The subungual areas of the hand harbor high concentrations of bacteria, most frequently coagulase-negative staphylococci, gram-negative rods (including Pseudomonas spp.), Corynebacteria, and yeasts.

• Freshly applied nail polish does not increase the number of bacteria recovered from periungual skin, but chipped nail polish supports the growth of larger numbers of organisms on the fingernails.

• HCWs who wear artificial nails are more likely to harbor gram-negative pathogens on their fingertips than are those who have natural nails, both before and after handwashing

• Skin underneath rings is more heavily colonized than comparable areas of skin on fingers without rings. 
• One study found that 40% of nurses harbored gram-negative bacilli (e.g., E. cloacae, Klebsiella, and Acinetobacter ) on skin under rings and that certain nurses carried the same organism under their rings for several months.

Indications for Handwashing and Hand Antisepsis:

• When hands are visibly dirty or contaminated with proteinaceous material or are visibly soiled with blood or other body fluids, wash hands with either a non-antimicrobial soap & water or an antimicrobial soap & water.
• If hands are not visibly soiled, use an alcohol-based hand rub for routinely decontaminating hands.
• Decontaminate hands:
• Before having direct contact with patients. 
• Before donning sterile gloves when inserting a central intravascular catheter.
• Before inserting indwelling urinary catheters, peripheral vascular catheters, or other invasive devices that do not require a surgical procedure.
• After contact with a patient's intact skin (e.g., when taking a pulse or blood pressure, and lifting a patient).
• After contact with body fluids or excretions, mucous membranes, nonintact skin, and wound dressings if hands are not visibly soiled.
• If moving from a contaminated-body site to a clean-body site during patient care.
• After contact with inanimate objects (including medical equipment) in the immediate vicinity of the patient.
• After removing gloves.
• Before eating and after using a restroom, wash hands with a non-antimicrobial soap & water or with an antimicrobial soap & water.

• Antimicrobial-impregnated wipes (i.e., towelettes) may be considered as an alternative to washing hands with non-antimicrobial soap & water.

• Wash hands with non-antimicrobial soap & water or with antimicrobial soap & water if exposure to Bacillus anthracis is suspected or proven. 

• When decontaminating hands with an alcohol-based hand rub, apply product to palm of one hand and rub hands together, covering all surfaces of hands and fingers, until hands are dry. Follow the manufacturer's recommendations regarding the volume of product to use.

• When washing hands with soap and water , wet hands first with water, apply an amount of product recommended by the manufacturer to hands, and rub hands together vigorously for at least 15 seconds, covering all surfaces of the hands and fingers. Rinse hands with water and dry thoroughly with a disposable towel. Use towel to turn off the faucet. Avoid using hot water, because repeated exposure to hot water may increase the risk of dermatitis.

• Remove rings, watches, and bracelets before beginning the surgical hand scrub.
• Remove debris from underneath fingernails using a nail cleaner under running water.
• Surgical hand antisepsis using either an antimicrobial soap or an alcohol-based hand rub with persistent activity is recommended before donning sterile gloves when performing surgical procedures.
• When performing surgical hand antisepsis using an antimicrobial soap, scrub hands and forearms for the length of time recommended by the manufacturer, usually 2-6 minutes. Long scrub times (e.g., 10 minutes) are not necessary.
• When using an alcohol-based surgical hand-scrub product with persistent activity, follow the manufacturer's instructions. Before applying the alcohol solution, prewash hands and forearms with a non-antimicrobial soap and dry hands and forearms completely. After application of the alcohol-based product as recommended, allow hands and forearms to dry thoroughly before donning sterile gloves.

• Provide HCWs with hand lotions or creams to minimize the occurrence of irritant contact dermatitis associated with hand antisepsis or handwashing.
• Solicit information from manufacturers regarding any effects that hand lotions, creams, or alcohol-based hand antiseptics may have on the persistent effects of antimicrobial soaps.

• Do not wear artificial fingernails or extenders when having direct contact with patients at high risk (e.g., those in intensive-care units or operating rooms).
• Keep natural nails tips less than 1/4-inch long).
• Wear gloves when contact with blood or other potentially infectious materials, mucous membranes, and nonintact skin could occur.
• Remove gloves after caring for a patient. Do not wear the same pair of gloves for the care of more than one patient, and do not wash gloves between uses with different patients.
• Change gloves during patient care if moving from a contaminated body site to a clean body site.
• No recommendation can be made regarding wearing rings in health-care settings. 

• Begin with washing hands with plain soap to remove dirt and debris.
• In between hand washing with plain soap, clean hands using alcohol-based hand gels.
• Alcohol-based hand gels may be used to clean the hands between several activities or patient contacts.
• Alcohol-based hand gels may be used before and after gloving to perform routine activities and procedures.
• Wash hands with plain soap whenever hands are visibly dirty or begin to feel gritty (i.e., as if there is a build-up of the gel on them).
• Alcohol loses its effectiveness in the presence of dirt and organic matter.
• Use hand lotions to support good skin health.
• Make certain the lotion is not contaminated.
• Lotions used with products containing chlorhexidine gluconate (CHG) must be selected to avoid neutralization by anionic surfactants.
• Based on what has been learned through research and practice, the current recommendation with regard in clinical areas such as the operating room and neonatal and transplant units is:
• Shorter, less traumatic washing regimens may be used instead of lengthy scrub protocols with brushes or other harsh mechanical action.

• The purpose of hand washing is to remove dirt, organic matter, and transient microorganisms.
• Transient flora do not normally colonize the skin (i.e., multiply in high numbers) and the types of transient flora found on the skin vary from person to person.
• These transient flora can be transmitted by a health care worker's hands unless they are removed by proper hand washing.
• Proper hand washing includes mechanical friction, use of appropriate soap, proper rinsing and drying.
• The facility you work in will determine when a plain soap is OK and when an antimicrobial soap (or water-less antiseptic agent) is required.
• Washing:
• Use warm water.
• Your dampened hands should be thoroughly covered with the hand washing substance (3 to 5 ml is recommended), then rubbed vigorously for 10 to 15 seconds, generating friction on all surfaces of the hands and fingers.
• Fingernails should be thoroughly cleaned. Washing should proceed from the tips of the fingers up to and including the wrists.
• Rinsing:
• Use warm water.
• Rinsing should begin from the fingertips downward to the wrists.
• Hands should be thoroughly rinsed to remove soap and debris. (Note: Some hand washing procedures include the cleansing of the forearms.)
• Drying:
• Hands should be dried using paper towels.
• Drying should proceed from the tips of the fingers up to and including the wrists.
• A paper towel should be used to turn off the faucet, trying not to contaminate the hands.
• Sinks with foot controls or automatic shutoff are best.
• Warm-air dryers are used in public rest rooms, but are rarely employed in the health care setting.
• These type of dryers dry the hands slowly, often have timed cycles that are too brief, can only be used by one person at a time, and could cause organisms to be blown back onto the hands.

• The purpose of hand antisepsis is to remove or destroy transient microorganisms.
• There are two ways hand antisepsis can occur:
• During hand washing by using a soap or detergent containing an antiseptic ingredient in an appropriate concentration.
• By using an alcohol-containing antiseptic handrub on clean hands.
• Hand antisepsis using alcohol:
• This process requires the hands already be free of dirt.
• Alcohol is not a good cleaning agent, losing its effectiveness in the presence of dirt and organic matter.
• The recommended method:
• Thoroughly wet pre-cleaned hands with an alcohol solution.
• Vigorously rub the hands for one minute, generating friction on all surfaces of the hands and fingers.
• 60% to 70% ethanol or isopropyl alcohol preparations, containing emollients to minimize skin drying, are considered the best.
• The technique is only effective if a sufficient amount of alcohol, of an appropriate concentration, is used.

Gram Positive Cocci:

• The three main Gram positive cocci are: Staphylococcus, Streptococcus, and Enterococcus .
• Staphylococci :
• Staphylococci are divided into two major groups based on the coagulase test:
• Coagulase positive (CoPS), includes Staphylococcus aureus.
• Coagulase negative (CoNS) includes all other species of staph, including Staphyloccus epidermidis, S. saprophyticus , and S. haemolyticus.
• 30% of people carry S. aureus as normal flora of their nose.
• Staph species colonize skin, external eye, external ear, and mucous membranes.
• Staphylococcus aureus is the main cause of staph infections. Infections vary from skin infections to serious progressive, invasive diseases.
• Microscopically, Staphylococcus is a genus of Gram-positive, nonmotile, nonsporing cocci.  They are 0.5 - 1.5 micrometers (mm) in size and occur in grapelike clusters.  Sometimes those clusters are disturbed by the staining process, leaving staphylococci in singles, pairs, short chains, and tetrads, along with the clusters.
• We are most interested in three species of the genus Staphylococcus:   S. aureus,  S. epidermidis, and  S. saprophyticus.  When seen as colonies on Petri plates, all staph colonies are 1-3 mm in diameter.  They are opaque, smooth, convex, and circular.  They have a butyrous (buttery) appearance.   
• Colonies of Staphylococcus aureus are usually yellow to orange to white, plus they show beta-hemolysis on a blood agar plate.  
• Colonies of Staphylococcus epidermidis are usually gray-white and are nonhemolytic (called gamma-hemolysis) on a blood agar plate.  
• Colonies of Staphylococcus saprophyticus  are often yellow to orange and are also nonhemolytic on a blood agar plate.

• Staphylococci and Streptococci are distinguished using the catalase test:
• Staph are catalase positive while  Strep are catalase negative.
• This test demonstrates the ability of a bacterium to produce the enzyme, catalase, capable of converting hydrogen peroxide (produced as part of oxygen usage) to water and  oxygen.  Add several drops of 3% hydrogen peroxide drop-by-drop in the tube.  In a positive test, bubbling occurs along the streak.  The bacterium is  aerobic or facultatively anaerobic.  As part of its oxygen usage, it has produced hydrogen peroxide.  It then produced catalase enzyme to break down the hydrogen peroxide to water and oxygen.  In a negative test, no bubbling occurs.

• Streptococci :
• Microscopically, Streptococcus is a genus of Gram-positive, nonmotile, nonsporing cocci.  They are 0.5 - 2.0 micrometers in size and occurs in pairs or chains.  Often, especially in a young culture, they will appear elongated, ovoid to rodlike in shape.
  
  • We are most interested in four species of the genus Streptococcus: S. pyogenes, S. pneumoniae, S. mutans , and S. sanguis .  All Strep colonies are small, being around 0.5 mm in diameter.  When seen as colonies on Petri plates, they are transparent to opaque, smooth, and circular.   All Strep colonies are coagulase negative.  
  • Colonies of Streptococcus pyogenes (known as Group A Strep) are convex, usually show beta-hemolysis, with large areas of clearing that are two to four times the diameter of the colony.  
  • Colonies of Streptococcus pneumoniae (known as pneumococci) are flat, have a shiny, mucoid (mucus-like) appearance, and display alpha-hemolysis (greenish discoloration).  
  • Colonies of Streptococcus mutans and S. sanguis (known as viridans strep) are small, opaque, and gray to whitish-gray.  S. mutans is nonhemolytic, while S. sanguis is alpha-hemolytic.
• Beta-hemolytic Strep.
• Beta-hemolytic Strep include Lancefield Groups A (Streptococcus pyogenes), B ( Streptococcus agalactiae ), C, F, and G.
• Alpha-hemolytic Strep.
• Alpha-hemolytic Strep include Streptococcus pneumoniae and the viridans strep ( S. mutans, S. salivaricus, S. sanguis, S. mitis, and S. oralis ).
• Group A Strep ( Streptococcus pyogenes) are not usually considered part of a person's normal flora. They are the main cause of strep infections, especially strep throat (streptococcal pharyngitis).

• Enterococci:
•   Enterococcus faecalis and Enterococcus faecium are the two most common species of Enterococci.
• Enterococci are found as normal flora of the skin, mucous membranes, and GI tract.
• Nosocomial infections involving Enterococci include UTIs, wound infections, intra-abdominal infections, and bloodstream infections.

• Listeria monocytogenous is the most common species of Listeria associated with human disease.
• Listeria can resist cold and salt, which allows them to survive through the processing and storage of food products.
• Listeria monocytogenous can cause bloodstream infections and meningitis in neonates and immunocompromised patients. In pregnant women, infections can result in abortion, still birth, or premature birth.
• Corynebacterium diphtheriae causes diphtheria.  Due to the administration on the DTaP vaccine, diphtheria is very rare in the United States.
• Facts about Anthrax:
• Bacillus anthracis is the cause of anthrax. Anthrax is a disease usually associated with animals that can spread to humans in close contact with infected animals.
• Bacillus anthracis has been implicated in biological warfare.
• The endospores gain entry through cuts or through mucous membranes.
• Human infections usually occur in workers whose occupations expose them to infected animals (ex: farmers, veterinarians, and slaughter house personnel) or animal products (hides, wook, or hair).
• The infection begins as lesions, then spreads through the lymphatic system to the bloodstream.
• 5 to 20% of untreated cases result in death.
• Signs and symptoms of Anthrax:
• Symptoms of disease vary depending on how the disease was contracted, but symptoms usually occur within 7 days.
• Cutaneous anthrax is the most common naturally occurring type of infection (>95%) and usually occurs
after skin contact with contaminated meat, wool, hides, or leather from infected animals. The incubation period ranges from 1-12 days. The skin infection begins as a small papule, progresses to a vesicle in 1-2 days followed by a necrotic ulcer. The lesion is usually painless, but patients also may have fever, malaise, headache, and regional lymphadenopathy. Most (about 95%) anthrax infections occur when the bacterium enters a cut of abrasion on the skin. Skin infection begins as a raised bump that resembles a spider bite, but (within 1-2 days) it develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a characteristic black necrotic (dying) area in the center. Lymph glands in the adjacent area may swell. About 20% of untreated cases of cutaneous anthrax will result in death. Deaths are rare if patients are given appropriate antimicrobial therapy.
• Inhalational anthrax is the most lethal form of anthrax. Anthrax spores must be aerosolized in order to cause inhalational anthrax. The number of spores that cause human infection is unknown. The incubation period of inhalational anthrax among humans is unclear, but it is reported to range from 1 to 7 days, possibly ranging up to 60 days. It resembles a viral respiratory illness and initial symptoms include sore throat, mild fever, muscle aches and malaise. These symptoms may progress to respiratory failure and shock with meningitis frequently developing.
• Gastrointestinal anthrax usually follows the consumption of raw or undercooked contaminated meat and has an incubation period of 1-7 days. It is associated with severe abdominal distress followed by fever and signs of septicemia. The disease can take an oropharyngeal or abdominal form. Involvement of the pharynx is usually characterized by lesions at the base of the tongue, sore throat, dysphagia, fever, and regional lymphadenopathy. Lower bowel inflammation usually causes nausea, loss of appetite, vomiting and fever, followed by abdominal pain, vomiting blood, and bloody diarrhea.

• Colonization means that the organism is present in or on the body but is not causing illness. Infection means that the organism is present and is causing illness.
• The 4 common Gram positive multi-drug resistant cocci are:
• MRSA  - Drug-resistant forms of Staphylococcus aureus
• DRSP - Drug-resistant forms of Streptococcus pneumoniae
• VRE - Drug-resistant forms of Enterococcus faecalis and Enterococcus faecium
• CoNS - Drug-resistant forms of Coagulase-Negative Staphylococcus (S. epidermidis, S. haemolytica & S. hominis)

• MRSA:
• The most important reservoirs of MRSA are infected or colonized patients.
• Hospital personnel can serve as reservoirs for MRSA and may harbor the organism for many months.
• Hospital personnel have been more commonly identified as a link for transmission between colonized or infected patients.
• The main mode of transmission of MRSA is via hands (especially health care workers' hands) which may become contaminated by contact with:
• Colonized or infected patients.
• Colonized or infected body sites of the personnel themselves.
• Devices, items, or environmental surfaces contaminated with body fluids containing MRSA.

• Community-Acquired MRSA:
• Humans are a natural reservoir for S. aureus.
• Asymptomatic colonization is far more common than infection.
• Colonization occurs in the nasopharynx, perineum, or skin:
• If the cutaneous barrier has been disrupted or damaged
• May occur shortly after birth and may recur anytime thereafter.
• Family members of a colonized infant may also become colonized.
• Transmission occurs by direct contact with a colonized carrier.
• Carriage rates (i.e. colonized carriers) are 25% to 50%.
• Carriage rates higher than in the general population are observed in:
• Injection drug users
• Persons with insulin-dependent diabetes
• Patients with dermatologic conditions
• Patients with long-term indwelling intravascular catheters
• Health-care workers
• Young children tend to have higher colonization rates, probably because of their frequent contact with respiratory secretions.
• Colonization may be transient or persistent and can last for years.

• VISA and VRSA:
• Vancomycin-Intermediate Staphylococcus aureus (VISA) are not susceptible to vancomycin.
• Therefore, vancomycin treatment is not reliable for treating these infections.
• However, to date, all VISA isolates have been susceptible to other FDA-approved antimicrobial drugs.
• Vancomycin-resistant Staphyloccus aureus (VRSA) are resistant to vancomycin.
• These organisms have not yet been found in nature but might emerge from VISA.
• Vancomycin would not be effective at all for treating these infections.

• DRSP:
• Drug Resistant Streptococcus pneumoniae are resistant to one or more commonly used antibiotics.
• Seven sero-types (6A, 6B, 9V, 14, 19A, 19F, and 23F) account for most DRSP. Since 1987, the incidence of DRSP has increased in the United States.
• Of the S. pneumoniae infections that occur, up to 40% are caused by DRSP.
• The totals for S. pneumoniae infections each year include100,000-135,000 hospitalizations for pneumonia, 6 million cases of otitis media, and over 60,000 cases of invasive disease, including 3300 cases of meningitis.
• Death occurs in 14% of hospitalized adults with invasive disease.

• VRE:
• Since 1989, a rapid increase in the incidence of infection and colonization with Vancomycin-Resistant Enterococci (VRE) has been reported from U.S. hospitals.
• This increase poses two major problems:
• The lack of available antimicrobials for treatment of infections caused by VRE, because most VRE are also resistant to multiple other drugs.
• The possibility that the vancomycin-resistance genes present may be transferred to other Gram-positive microorganisms such as Staphylococcus aureus.

• CoNS:
• Central venous catheters are the instrument associated with most hospital-acquired bloodstream infections, with the most common causative agent being Coagulase-Negative Staphylococcus epidermidis.
• The mortality rate among infected patients is estimated at 35%.

• There are 14 Gram positive bacterial diseases we will concentrate on in this course.These diseases were assigned as part of a group activity. You should receive information on these diseases from your classmates.
• For each disease you must know the following:  1) name of disease, 2) causative agent(s) and its description, 3) symptoms, 4) incubation period, 5) pathogenesis, 6) epidemiology, 7) treatment (Note: Be specific!), 8) prevention, 9) control, and 10) isolation precautions employed in a healthcare setting for the disease (including information contained in footnotes).

• Scalded Skin Syndrome (also known as Ritter's Disease)                                                         
  
• Toxic Shock Syndrome (TSS)                                                                                                                                                                               
  
• Note: Name the toxin produced in TSS. Explain when/how TSS can result from surgeries.
• Staphylococcal Wound Infections, caused by Staphylococcus aureus & Staphylococcus epidermidis
  
• Note: Distinguish between types of wound infections caused by S. aureus and wound infections caused by S. epidermidis.
• Subacute Bacterial Endocarditis (SBE)                                                                                   
  
• Streptococcal Pyoderma, including Impetigo                                                                          
  
• Note: Distinguish between streptococcal pyoderma and impetigo.
• Streptococcal Pharyngitis (also known as Strep Throat)                                                                
  
• Necrotizing Fasciitis (also known as Streptococcal Gangrene or Flesh-Eating Disease)                 
  
• Streptococcal Toxic Shock Syndrome (STSS)                                                                                                                                      
  
• Streptococcal Pneumonia (also known as Pneumococcal Pneumonia)                                            
  
• Dental Caries, leading to Periodontal Disease & Acute Necrotizing Ulcerative Gingivitis (ANUG,  known as Trench Mouth or Vincent's Disease)
  
• Note: Distinguish between dental caries, periodontal disease, and ANUG. Explain when/how each develops, the bacteria involved, and the treatments for each.
• Neonatal Sepsis, Early or Late Onset (also known as Group B Streptococcal Disease (GBS)           
  
• Note: Distinguish between Early and Late Onset of Neonatal Sepsis as to transmission, symptoms and treatment.
  
• Diphtheria                                                                                                                                   
  
• Note: You must discuss the diphtheria vaccination schedule (number of shots & when given) for children, adolescents, and adults. Distinguish between when DTaP is used and Td is used.
• Anthrax                                                                                                                 
  
• Note: Discuss the three forms of anthrax (respiratory, cutaneous, and gastrointestinal), including how each is transmitted, its symptoms, and treatment. Discuss the use of anthrax in bioterrorism.
  
• Listeriosis                                                                                                                                   
  
•  Note: Discuss the problems of Listeriosis related to pregnancy.

• A standard is defined in Webster's Dictionary as "an authoritative principle or rule that usually implies a model or pattern for guidance, by comparison with which the quantity, excellence, correctness, etc. of other things may be determined."
• Wherever you work in healthcare, now or in the future, there is an Exposure Control Manual that has been written for that facility. You should be aware of its existence. It was written to protect you as a healthcare worker. As part of your orientation to the facility as a new worker, you should become familiar with the document. You should locate it and read it. Facility exposure control manuals are based upon the OSHA and MIOSHA standards.
• On December 6,1991, OSHA published the Occupational Exposure to Bloodborne Pathogens Standard in 29 CFR Part 1910.1030, Subpart Z, of the Federal Register. This rule provided guidelines for facilities to reduce the risk of infection of employees exposed to body fluids and tissues from infected persons, or equipment and surfaces that may have been contaminated.
• On June 30, 1993, MIOSHA filed the Standard For Bloodborne Infectious Diseases, in R 325.70001-R 325.700018 of the Michigan Administrative Code, which was based on the OSHA rule.
• These rules address definitions, work practices, procedures, equipment and policies related to staff training, information dissemination, preventative and post-incident medical interventions. The objective is to minimize risk of exposure or, if necessary, to effectively treat employees involved in an incident where there is a significant possibility of exposure.
• As the CDC updates its guidelines, OSHA & MIOSHA update their standards through interpretations to stay in alignment with CDC information. This is a continual process of adaptation and change! You must be aware of, and prepared for, this continuous process of change as a healthcare worker. You must continue your process of education through updates and course work.
• Over the years, both the OSHA and MIOSHA rules have been subject to interpretations and revisions, based on further knowledge of infectious diseases and their transmission. The targeted diseases now include hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and other bloodborne diseases.
• Along with setting standards for the nation, OSHA carries the responsibility of seeing that these standards are enforced.  To that end, OSHA has writen a directive used to enforce the Occupational Exposure to Bloodborne Pathogens Standard.  This directive establishes policies and provides clarification to ensure uniform inspection procedures are followed when conducting inspections. This directive is called: Enforcement Procedures for the Occupational Exposure to Bloodborne Pathogens.   To fully understand the standard, you must look at its accompanying directive. The OSHA directive regarding occupational exposure to bloodborne pathogens was revised and became effective on November 5, 1999.
• The Occupational Safety and Health Administration revised the Bloodborne Pathogens Standard in conformance with the requirements of the Needlestick Safety and Prevention Act of November 6, 2000. The revised standard was entitled: Occupational Exposure to Bloodborne Pathogens; Needlestick and Other Sharps Injuries; Final Rule.  It was published in the Federal Register on January 18, 2001, Volume 66, No. 12, pages 5318 to 5325.   The effective date for the revised standard was April 18, 2001.
• MIOSHA revised the Standard For Bloodborne Infectious Diseases on February 6, 2001, to be in compliance with the OSHA revision.  The revised Michigan standard became effective on October 18, 2001.

• The link to the OSHA document:  1910.1030 - Bloodborne pathogens.
• OSHA Standard Number: 1910.1030. Standard Title: Bloodborne pathogens. SubPart Number: Z. SubPart Title: Toxic and Hazardous Substance.
• Scope: Applies to all occupational exposure to blood or other potentially infectious materials.
• Occupational Exposure involves reasonably anticipated skin, eye, mucous membrane, or parenteral contact with blood or other potentially infectious materials that may result from the performance of an employee's duties.
• Other Potentially Infectious Materials include:
• The following human body fluids: semen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural fluid, pericardial fluid, peritoneal fluid, amniotic fluid, saliva in dental procedures.
• Any body fluid that is visibly contaminated with blood.
• All body fluids in situations where it is difficult or impossible to differentiate between body fluids.
• Any unfixed tissue or organ (other than intact skin) from a human (living or dead).
• HIV-containing cell or tissue cultures, organ cultures, and HIV- or HBV-containing culture medium or other solutions; and blood, organs, or other tissues from experimental animals infected with HIV or HBV.
• Personal Protective Equipment (PPE) is specialized clothing or equipment worn by an employee for protection against a hazard.
• Engineering controls are controls that isolate, minimize or remove a workplace hazard. They are controls which deal with the physical environment, including buildings and equipment.
• Work-practice controls are controls that reduce exposure by altering the manner in which a task is performed. They relate to the employee's training and behavior.
• An Exposure Control Plan should contain the following elements:
• The exposure determination.
• The schedule and method of implementation for:
• Methods of Compliance.
• HIV and HBV Research Laboratories and Production Facilities.
• Hepatitis B Vaccination and Post-Exposure Evaluation and Follow-up.
• Communication of Hazards to Employees.
• Recordkeeping.
• The procedure for the evaluation of circumstances surrounding exposure incidents.
• Communication of Hazards to Employees:
• This communication includes labels and signs, information, and training.
• According to the standard, training must be provided:
• At the time of initial assignment to tasks where occupational exposure may take place
• Annually thereafter
• When modification of tasks, or new tasks, affect the employee's occupational exposure
• Regulated medical waste includes:
• Liquid or semi-liquid blood or other potentially infectious materials.
• Contaminated items that would release blood or other potentially infectious materials in a liquid or semi-liquid state if compressed.
• Items that are caked with dried blood or other potentially infectious materials and are capable of releasing these materials during handling.
• Contaminated sharps.
• Pathological and microbiological wastes containing blood or other potentially infectious materials.

• The link to the MIOSHA document: http://www.michigan.gov/documents/CIS_WSH_part554_35632_7.pdf
• Written by the Occupational Health Standards Commission, under the authority of section 24 of Act No. 154 of the Public Acts of 1974, as amended, being S408.1024 of the Michigan Compiled Laws. Contains R 325.70001 - R 325.70018.
• Exposure determination:
• An employer shall evaluate routine and reasonably anticipated tasks and procedures to determine whether there is actual, or reasonably anticipated, employee exposure to blood or other potentially infectious material. An employer shall categorize all employees into category A or B.
• Category A consists of occupations that require procedures or other occupation-related tasks that involve exposure, or reasonably anticipated exposure, to blood or other potentially infectious material, or that involve a likelihood for spills or splashes of blood or other potentially infectious material. This includes procedures or tasks conducted in nonroutine situations as a condition of employment.
• Category B consists of occupations that do not require tasks that involve exposure to blood or other potentially infectious material on a routine or nonroutine basis as a condition of employment. Employees in occupations in this category do not perform or assist in emergency medical care or first aid and are not reasonably anticipated to be exposed in any other way.
• Vaccinations and postexposure follow-up:
• An employer shall assure that all medical evaluations and procedures are performed by or under the supervision of a licensed physician or other licensed health care professional and that all laboratory tests are conducted by an accredited laboratory.
• An employer shall assure that all evaluations, procedures, vaccinations, and postexposure prophylaxes are provided without cost to the employee, at a reasonable time and place, and according to current recommendations of the United States public health service.

• OSHA revised the Bloodborne Pathogens Standard in conformance with the requirements of the Needlestick Safety and Prevention Act of November 6, 2000.
• The revised standard was entitled: Occupational Exposure to Bloodborne Pathogens; Needlestick and Other Sharps Injuries; Final Rule.
• It was published in the Federal Register on January 18, 2001, Volume 66, No. 12, pages 5318 to 5325.
• The effective date for the revised standard was April 18, 2001.
• In the revised standard, engineering controls means:
• Controls (e.g., sharps disposal containers, self-sheathing needles, safer medical devices, such as  sharps with engineered sharps injury protections and needleless systems) that isolate or remove the bloodborne pathogens hazard from  the workplace.
• In the revised standard, needleless systems means:
• A device that does not use needles for:
• The collection of bodily fluids or withdrawal of body fluids after initial venous or arterial access is established.
• The administration of medication or fluids.
• Any other procedure involving the potential for occupational exposure to bloodborne pathogens due to percutaneous injuries from contaminated sharps.
• In the revised standard, "sharps with engineered sharps injury protections" means:
• A nonneedle sharp or a needle device used for withdrawing body fluids, accessing a vein or artery, or administering medications or other fluids, with a built-in safety feature or mechanism that effectively reduces the risk of an exposure incident.
• In the revised standard, the Exposure Control Plan:
• Shall be reviewed and updated at least annually and whenever necessary to reflect new or modified tasks and procedures which affect occupational exposure and to reflect new or revised employee positions with occupational exposure. The review and update of such plans shall:
• Reflect changes in technology that eliminate or reduce exposure to bloodborne pathogens.
• Document annually consideration and implementation of appropriate commercially available and effective safer medical devices designed to eliminate or minimize occupational exposure.
• An employer shall solicit input from non-managerial employees responsible for direct patient care who are potentially exposed to injuries from contaminated sharps in the identification, evaluation, and selection of effective engineering and work practice controls.
• In the revised standard, the rules for sharps injury logs include:
• The employer shall establish and maintain a sharps injury log for the recording of  percutaneous injuries from contaminated sharps. The information in the sharps injury log shall be recorded and maintained in such manner as to protect the confidentiality of the injured employee. The sharps injury log shall contain, at a minimum:
• The type and brand of device involved in the incident.
• The department or work area where the exposure incident occurred.
• An explanation of how the incident occurred.

• MIOSHA's revised Standard For Bloodborne Infectious Diseases was released on February 6, 2001, to be in compliance with the OSHA revision and in conformance with the requirements of the Needlestick Safety and Prevention Act of November 6, 2000.
• The revised Michigan standard became effective on October 18, 2001.
• MIOSHA's revisions were aligned with OSHA's revision.
• In the revised standard, engineering controls means:
• Controls (e.g., sharps disposal containers, self-sheathing needles, safer medical devices, such as  sharps with engineered sharps injury protections and needleless systems) that isolate or remove the bloodborne pathogens hazard from  the workplace.
• In the revised standard, needleless systems means:
• A device that does not use needles for:
• The collection of bodily fluids or withdrawal of body fluids after initial venous or arterial access is established.
• The administration of medication or fluids.
• Any other procedure involving the potential for occupational exposure to bloodborne pathogens due to percutaneous injuries from contaminated sharps.
• In the revised standard, "sharps with engineered sharps injury protections" means:
• A nonneedle sharp or a needle device used for withdrawing body fluids, accessing a vein or artery, or administering medications or other fluids, with a built-in safety feature or mechanism that effectively reduces the risk of an exposure incident.
• In the revised standard, the Exposure Control Plan:
• Shall be reviewed and updated at least annually and whenever necessary to reflect new or modified tasks and procedures which affect occupational exposure and to reflect new or revised employee positions with occupational exposure. The review and update of such plans shall:
• Reflect changes in technology that eliminate or reduce exposure to bloodborne pathogens.
• Document annually consideration and implementation of appropriate commercially available and effective safer medical devices designed to eliminate or minimize occupational exposure.
• An employer shall solicit input from non-managerial employees responsible for direct patient care who are potentially exposed to injuries from contaminated sharps in the identification, evaluation, and selection of effective engineering and work practice controls.
• In the revised standard, the rules for sharps injury logs include:
• The employer shall establish and maintain a sharps injury log for the recording of  percutaneous injuries from contaminated sharps. The information in the sharps injury log shall be recorded and maintained in such manner as to protect the confidentiality of the injured employee. The sharps injury log shall contain, at a minimum:
• The type and brand of device involved in the incident.
• The department or work area where the exposure incident occurred.
• An explanation of how the incident occurred.