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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 1 Study Guide 

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Be Prepared For Questions on The Following :

• Reservoir of Infection and Source of Infection:
• Explain the meaning of reservoir of infection and source of infection
• Use Salmonella typhi to explain the differences between the reservoir and the source of the infection
• Carriers:
• The three ways that the carrier state can occur: incubation, convalescence and chronic
• Give examples of diseases for each carrier state
• Vectors:
• The diffferent types of vectors: arthropods (fleas, mosquitos, flies and ticks), birds, and lower vertebrates (frogs and turtles)
• Give examples of diseases for each vector type
• Zoonoses:
• Explain zooneses
• Give examples of zoonotic diseases
• Communicable and Non-Communicable Diseases:
• What a communicable disease is and how its transmission can occur
• Give examples of communicable diseases
• Give examples of non-communicable diseases
• Know the differences between sporadic disease, endemic disease, epidemic disease and pandemic disease
• Horizontal and Vertical Transmission:
• What it means to say that most transmission is usually horizontal
• The situations where vertical transmission occurs: mother to child in utero and/or in breast milk
• Examples for direct, airborne, droplet, vectorborne and common vehicle transmission
• Compare and contrast airborne and droplet transmission
• Antigenic Shift and Antigenic Drift:
• Compare and contrast antigenic shift and antigenic drift
• Give examples of both antigenic shift and antigenic drift
• Bacterial Shapes:
• Know what determines the shape of the bacterial cell.
• Name and describe the three types of bacterial shapes.
• Define pleomorphism.

• Bacterial Cell Walls:
• Know the functions of the cell wall.
• Describe the peptidoglycan layer of the Gram positive cell wall.
• Describe the LPS (lipopolysaccharide) layer of the Gram negative cell wall, including the O antigen and lipid A.
• Describe wall-less bacteria, such as Mycoplasma.

• Introduction to the Immune System:
• Describe the role of the O antigen in stimulating an immune response.
• Describe antigens and antibodies.
• Know the two pathways for specific immune responses: B-cell & T-cell responses.

• Endotoxins:
• Describe the role of lipid A as an endotoxin.
• Describe when endotoxins are released in the body.
• Describe what it means to say that endotoxins are heat stable, what this means with regard to autoclaving and IV fluids.

• Exotoxins:
• Compare and contrast exotoxins and endotoxins.
• Describe what  exotoxins are composed of.
• Describe neurotoxins and enterotoxins.
• Describe which kinds of bacteria can produce exotoxins.
• Describe the 3 types of exotoxins:  A-B exotoxins, membrane-damaging exotoxins, and superantigen exotoxins.
• Describe the subtypes of A-B exotoxins: neurotoxins, enterotoxins, and cytotoxins.
  
• Be able to name diseases associated with each of the 3 types of exotoxins:  A-B exotoxins, membrane-damaging exotoxins, and superantigen exotoxins.

• Slime Layers and Biofilms:
• Describe a slime layer.
• Know how slime layers form biofilms and create problems in healthcare and in industry.
• Describe when and how Staphylococcus epidermidis forms a biofilm.
• Know what percentage of bacterial infections are estimated to involve formation of biofilms.
• Name bacteria associated with venous catheter biofilm infections.
• Name bacteria associated with mechanical heart biofilm infections.
• Name bacteria associated with urinary catheter biofilm infections.

• Bacterial Capsules:
• Describe a bacterial capsule.
• Explain how the capsule of Streptococcus mutans helps in the formation of dental plaque.
• Explain how the capsule of Streptococcus pneumoniae helps to cause infection.
• Define virulence and avirulence.
• Describe pathogenicity and pathogens.

• Fimbriae:
• Describe the composition and purpose of fimbriae.
• Describe the function of the fimbriae of Moraxella catarrhalis.
• Describe the function of the fimbriae of Neisseria gonorrhoeae.

• Sex Pili:
• Describe the composition and purposes of sex pili.
• Know what types of bacteria have sex pili.
• Describe the process of conjugation, as it occurs in bacteria such as E. coli.

• Flagella:
• Describe the purposes of flagella.
• List and explain the four types of flagellation.

• The Five Kingdoms:
• Describe the meaning of the terms "prokaryotes" and "eukaryotes."
• Compare and contrast prokaryotic and eukaryotic cells.
• Name and describe the 5 Kingdoms: Procaryotae, Protista, Mycetae (Fungi), Plantae, and Animalia.

• The Microbial World:
• Describe the composition of the microbial world.
• Distinguish between living  and nonliving infectious agents.

• Viruses, Viroids & Prions:
• Compare and contrast the three acellular nonliving infectious agents: viruses, viroids, and prions.
• Know the kinds of diseases caused by viruses, viroids, and prions.
• Know what CJD is, how it is caused, and how it can be accidentally transferred.
• Know the chemical and autoclave sterilization methods used to control TSEs (for disposable items, surfaces, heat-resistant items, and heat-sensitive items).
• Know what Chronic Wasting Disease is, how it is caused, and who gets infected.

• Nomenclature:
• Explain the binomial system of nomenclature and give one example of it.
• Explain what bacterial strains are.
• Define the words:  streptococcus, diplococcus, and staphylococcus.

• Staining Procedures:
• Define stain, chromophore, basic dye, acidic dye, simple staining procedure, positive staining, negative staining, and differential staining procedure.
• Define the primary stain, mordant, decolorizing agent, and counterstain (also known as the secondary stain) of the differential staining procedure.
• Know the steps of the Gram stain procedure, plus be able to name the staining agent used in each step.
• Know the medical importance of the Gram stain

• Bacterial Reproduction & the Chromosome:
• Define binary fission.
• Describe the bacterial chromosome.
• Describe the nucleoid of the bacterial cell.

• Plasmids:
• Describe plasmids.
• Describe R plasmids.
• Describe conjugation and its association with plasmids.

• Endospores:
• Describe the composition and function of endospores.
• Name the two genera of Gram positive bacilli that are endospore-formers.
• Define sporulation, endospore, germination, and vegetative cell.

• Mechanical & Chemical Control Mechanisms of the Skin, Eyes, Upper Respiratory Tract, GI Tract, and Genitourinary Tract:
• Know the differences between innate (nonspecific) and acquired (specific) immunity.
• Explain why the normal flora of the skin is usually Gram positive.
• Name where lysozyme is naturally found and the action of lysozyme.
• Name and describe the six mechanical and chemical control mechanisms used in the upper respiratory tract.
• Explain why most bacteria cannot survive passage through the stomach.
• Explain why most of the flora of the intestine are Gram negative, plus why Enterococci (a Gram positive) can survive.
• Explain a control mechanism within the urinary tract.
• Inflammatory Response:
• List the classic signs of inflammation.
• List the 4 chemical mediators of inflammation and the types of cells from which they come.
• Describe the general sequence of events involved in inflammatory response.
• Describe abscess formation and the components of the abscess.
• List and describe the 3 types of granular leukocytes, also known as PMNs (polymorphonuclear leukocytes).
• List and describe the two types of functional phagocytic cells as to morphology, location in the body, and function.
• Describe NK cells.
• Describe the steps involved in phagocytosis.
• The Reticuloendothelial System (RES), also known as the Mononuclear Phagocytic System (MPS):
• Describe the Reticuloendothelial System (RES), also known as the Mononuclear Phagocytic System (MPS).
• List the organs and types of cells comprising the RES (MPS).
• Primary Lymphoid Organs, Secondary Lymphoid Organs, and the Lymphatic System:
• Name the primary lymphoid organs.
• Name the secondary lymphoid organs.
• Name the secondary lymphoid tissues.
  
• Describe where the lymphatics connect to the circulatory system.
• Acquired (Specific or Adaptive) Immune Response:
• Describe the two arms of the acquired (specific or adaptive) immune response.
• Explain how B cells function and the types of cells that are formed through humoral (antibody-mediated) response.
• Explain how T cells function and the types of cells that are formed through cell-mediated response.
• Describe immunological memory (i.e., formation of memory cells).
• Describe antigens.
• Know the Y-shaped structure of a typical antibody.
• List the 5 classes of antibodies.
• List the primary functions for the 5 classes of antibodies.
• List the number of "Y" units for the 5 classes of antibodies.
• List the classes of antibodies which are involved in complement fixation. Indicate which class involves the use of alternative pathway.
• List the class of antibody which is involved in antibody-dependent cell-mediated cytotoxicity (ADCC).
• List the class of antibody which is involved in placental transfer.
• Describe how macrophages and monocytes are involved in antigen processing.
• Describe how activated B cells process antigen.
• Describe how dendritic cells process antigen.
• Describe how primary antibody response occurs.
• Describe how the secondary antibody response occurs.
• Know the other names given to the secondary antibody response.
• Be able to interpret the graph of the primary and secondary antibody responses.
• Antibody-Mediated Reactions:
• Describe the process of agglutination.
• Discribe the process of precipitation.
  
• Describe the process of opsonization.
• Describe the process of neutralization.
• The Complement System:
• Describe the classical pathway of complement.
• Discuss the roles of C3a, C5a, and C3b.
• Describe what the MAC complex is and its role in complement.
  
• Cell-Mediated Reactions:
• Describe T Helper cells.
• Describe how activated T helper cells are divided into TH-1 and TH-2 helper cells.
  
• Describe T Suppressor cells.
• Describe Cytotoxic T cells.
• Describe Delayed Hypersensitivity T cells.
• Hypersensitivity Reactions:
• Describe the four types of hypersensitivity reactions, tell if they are antibody or cell-mediated, and give examples of diseases for each type.
• Type I Hypersensitivity Reactions:
• Know what % of people suffer from allergies.
• List common allergens.
• List ways that allergens can enter the body.
• Describe allergen processing, which leads to the formation of IgE antibodies.
• Explain the role of IgE and mast cells.
• Explain what occurs the next time the person encounters the same allergen.
• Name the preformed chemical mediators which are released from activated mast cells during an allergic (type I) response. (This is known as mast cell degranulation.)
• List the results of mast cell degranulation on the body.
• Name the newly synthesized mediators that can be produced and released from mast cells after degranulation has occurred.
• Explain the differences between generalized, systemic anaphylactic reactions and localized reactions.
  
• List types of Type I Hypersensitivity reactions of blood vessels, the nose, the eyes, the lungs, the larynx, and the skin.
• Discuss hay fever, hives, and asthma.
• Type II Hypersensitivity Reactions:
• Name the types of antibodies involved.
• Describe the processes which are activated.
• For each type of disorder, list the cells whose antigens are targeted:
• Transfusion reactions
• Hemolytic disease of the newborn (Rh disease)
• Insulin-dependent diabetes (Juvenile diabetes)
• Type III Hypersensitivity Reactions:
• Describe the differences in antigen-antibody complexes in Type III.
• Name the types of locations within the body where the immune complexes typically become lodged.
• List and describe two autoimmune diseases which are Type III reactions.
• List infections which involve Type III reactions.
• List drug reactions which involve Type III reactions.
• Type IV Hypersensitivity Reactions:
• List examples of contact dermatitis which are Type IV reactions.
• List types of granulomatous diseases which are Type IV reactions.
• Explain how delayed hypersensitivity skin testing occurs, what it is used to test for reactivity to, the timing and size for a positive test, and what a positive test indicates.
• Antimicrobial Terminology:
  
• The following terms to be defined: antibiotic, antimicrobial, microcidal, microstatic, narrow spectrum antimicrobial, broad spectrum antimicrobial, extended spectrum antimicrobial, selective toxicity, synergism, MIC, MBC, susceptible (sensitive), resistant, and intermediate.
• Characteristics of Antimicrobials:
• The six characteristics of an ideal antibiotic.
• The beta lactam ring on penicillin and how penicillins differ from each other.
• The structural component cephalosporin shares with penicillin.
• How side chains on penicillins influence the spectrum of activity for the antibiotics.
• The development of the generations of cephalosporins and the progression in the spectrum of activity.
• Know what beta-lactamase is and how is causes drug resistance.
  
• Antimicrobial Testing:
• How a MIC test is run.
• How a MBC test is run.
• The Kirby-Bauer (KB) Disk Diffusion test.

• Environmental Conditions of Bacteria:
• Describe the following with regard to temperature and pH ranges: minimal, optimal, and maximal.
• Describe the temperature ranges for psychrophiles, mesophiles, and thermophiles.
• Describe the pH range of acidophiles, neutrophiles, and alkalophiles, and where each type would be found in the environment.
• Define halophilic and osmotolerant (also known as halotolerant).
• Describe the oxygen requirements of the following, plus give an example of a bacterium for each group:
• Obligate (Strict) Aerobes
• Microaerophiles
• Facultative Anaerobes
• Obligate (Strict) Anaerobes
• Aerotolerant Anaerobes

• Bacterial Growth:
• Explain generation time, plus give another name for generation time.
• Diagram and describe each of the phases of the bacterial growth curve:
• Lag phase
• Log Growth phase
• Stationary phase
• Log Death phase (or Decline)
• Describe lab tests in relation to the bacterial growth curve.
• Describe refrigeration and expiration dates in relation to the bacterial growth curve.

• Bacterial Cultures:
• Define mixed population (culture), pure culture, sterile, aseptic techniques, colony, agar, and Petri dish.
• Name and describe the three types of media based upon growth patterns.

• Normal Flora of the Body:
• Describe the resident flora of the body.
• Describe the transient flora of the body.
• List the germ-free areas of the body.

• Bacteria & Disease:
• Describe cross contamination and how it occurs.
• Describe what nosocomial infections are and how they occur.
• Know when primary pathogens can cause disease.
• Know when secondary pathogens can cause disease.
• List the 6 steps (links) involved in the chain of infection in the order in which they occur.
• Give examples of:  infectious agents, reservoirs of infection, portals of exit, means of transmission, portals of entry, and susceptible hosts.
• Know the four stages of a disease. Be able to describe the generalized characteristics of each stage
• Know the meaning of the following terms:  acute disease, chronic disease, latent disease, localized infection, systemic (or generalized) infection, symptoms of a disease, signs of a disease, syndrome, and communicable disease.
• Explain what virulence and virulence factors are.
  
• List several types of virulence factors of bacteria.

• C & S Testing:
• Know what the "C" and the "S" in C & S Testing stand for.
• Name the common methods employed to determine the identity of a microorganism.
• Explain what kinds of information the clinician gains through culture or biochemical testing.
• Know the factors which interfere with collecting viable specimens from patients.
• Explain what serological testing involves and what it's drawback is.
• Name the common types of antibiotic sensitivity testing.
• Explain what broth dilution testing involves.
• Explain what disk dilution testing involves.

• Genetic Recombination Methods of Bacteria:
• Define genetic exchange and list the three ways by which genetic exhange can occur in bacteria.
• Compare and contrast transformation, transduction, and conjugation.
• Describe the steps in bacterial conjugation.
• Describe what is different when an Hfr cross occurs during conjugation.
  
• Explain what R plasmids are and why they are such a problem in healthcare.
• Define the following terms: bacteriophage (shortened to phage), productive infection, lytic phage, lytic cycle, latent state, temperate phage, prophage, lysogen, lysogenic cycle, and lysogenic conversion.
  
• Describe the process of phage infection of bacteria leading to productive infection and culminating in lysis of the bacterial cell.
• Describe the process of phage infection of bacteria leading to a latent state.
• Describe generalized transduction.
• Name bacteria and diseases associated with lysogenic conversion.
  
• Describe the process of bacterial transformation.
• Define transposition.
  
• Describe transposons, plus what kind of genes are carried by bacterial transposons.

Required Essays:
1. Antimicrobials: Everyone is required to write one antimicrobial essay. Everyone will be given the chance to write on a second antimicrobial as an extra credit essay. In both cases (required and bonus buck essay), you choose the antimicrobial from the following list.

• Please discuss the following with regard to the antimicrobials: type of antimicrobial, examples of class, target site, mechanism of action, spectrum of activity, and drug resistance.

• The Antibacterials (Also known as Anti-infectives):  (Text Reference: p. 502-5)

• Penicillins:
• Natural Penicillins - such as Penicillin G & Penicillin V
• Penicillinase-Resistant Penicillins (PRPs) - such as Methicillin, Cloxacillin, Nafcillin, Oxacillin & Dicloxacillin
• Broad-Spectrum Penicillins - such as Ampicillin, Amoxicillin, Ampillicin + Sulbactam in combination, and Amoxicillin + Clavulanate potassium in combination
• Extended-Spectrum Penicillins - such as Mezlocillin, Ticarcillin & Piperacillin   
• NOTE: Be certain to discuss the four groups of penicillins and how they differ. Also, be certain to discuss the combinations (Ampillicin + Sulbactam and Amoxicillin + Clavulanate potassium).
• First, Second & Third Generation Cephalosporins:
• Fiirst Generation Cephalosporins - such as Cephalexin, Cefadroxil, Cefazolin, Cephalothin, Cephapirin & Cephradine
• Second Generation Cephalosporins - such as Cefaclor, Cefamandole, Cefmetazole, Cdfonicid, Cefoteten, Cefoxitin, Cefprozil, Cefurozime & Loracarbef
• Third Generation Cephalosporins - such as Cefdinir, Cefepime, Cefixime, Cefoperazone, Cefotaxime, Cefpodoxime, Ceftazidime, Cefibutin, Ceftizoxime, Ceftriazone & Moxalactam
• NOTE: Be certain to discuss the differences between the three generations of cephalosporins
• Sulfonamides (Sulfa Drugs, such as Sulfadiazine, Sulfamethoxazole, Sulfasalazine & Sulfisoxazole), Folate antagonists (such as Trimethoprim), and Trimethoprim + Sulfamethoxazole in combination
• NOTE: Be certain to discuss Trimethoprim + Sulfamethoxazole used in combination
• Aminoglycosides - such as Amikacin, Gentamicin, Kanamycin, Neomycin, Streptomycin & Tobramycin
• NOTE: Be certain to discuss the possible harmful side effects of some of these drugs
• Tetracyclines - such as Tetrcycline & Doxycycline
• Fluoroquinolones (Quinolones) - such as Ciprofloxacin, Ofloxacin, Alatrofloxacin, Enoxacin, Levofloxacin, Lomefloxacin, Nalidixic Acid, Norfloxacin & Sparfloxacin
• Macrolides - such as Erythromycin, Clarithromycin & Azithromycin
• Carbapenems - such as Meropenem & Imipenem + Cilastatin in combination
• NOTE: Be certain to explain the use of Imipenem + Cilastatin in combination
• Glycopeptides - such as Vancomycin
• Dichloroacetic acid derivatives - such as Chloramphenicol
• Lincosamides - such as Clindamycin
• Rifamycins - such as Rifampin & Rifabutin
  

• The Antivirals: (Text Reference: p. 513-4)

• Antiviral DNA Synthesis Inhibitors - such as Acyclovir (sold as Avirax and Zovirax), famciclovir (sold as Famvir), valacyclovir (sold as Valtrex), Cidofovir (sold as Vistide), Ganciclovir (sold as Cytovene), Ribavirin (sold as Virazole), Zalcitabine, known as ddC (sold as Hivid), and Zidovudine, known as AZT (sold as Retrovir and AZT)
• Antiviral Uncoating Inhibitors - such as Amantadine (sold as Symmetrel, Antadine, and Symadine) and rimantadine (sold as Flumadine)
• HIV Reverse Transcriptase Inhibitors - such as Didanosine, known as ddl (sold as Videx), Foscarnet (sold as Foscavir), Lamivudine (sold as Epivir), Nevirapine (sold as Viramune), and Stavudine, known as d4T (sold as Zerit)
• HIV Protease Inhibitors - such as Idinavir (sold as Crixivan), Ritonavir (sold as Norvir), and Saquinavir (sold as Invirase)

• The Antifungals:  (Text Reference: p. 515-6)

• Antifungal Azoles - such as Clotrimazole (sold as Mycelex, Lotrimin, etc), Ketoconazole (sold as Nizoral), Miconazole (sold as Monistat), Itraconazole (sold as Sporanox), and Fluconazole (sold as Diflucan)
• Antifungal Polyenes  - such as Amphotericin B (sold as Fungilin, Fungizone, Amphocin and Amphotericin B), and  Nystatin (sold as Nystat, Nilstat, Mycostatin, etc)
• Antifungal Penicillium derivatives - such as Griseofulvin (sold as Grisovin, Fulcin, etc.)

• The Antiprotozoals (Also known as Amebicides): (Text Reference: p. 513-4)

• Antiprotozoal DNA Synthesis Inhibitors - such as Metronidazole (sold as Metrozine, Protostat, etc), Pentamidine (sold as Pentam, Pneumopent, etc.) & Atovaquone (sold as Mepron)

• Type I Hypersensitivity Reactions:
• List common allergens.
• List ways that allergens can enter the body.
• Describe allergen processing, which leads to the formation of IgE antibodies.
• Explain the role of IgE and mast cells.
• Explain what occurs the next time the person encounters the same allergen.
• Name the preformed chemical mediators which are released from activated mast cells during an allergic (type I) response. (This is known as mast cell degranulation.)
• Name the newly synthesized mediators that can be produced and released from mast cells after degranulation has occurred.
• Explain the differences between generalized, systemic anaphylactic reactions and localized reactions.
  
• Discuss hay fever, hives, and asthma.
• Type II Hypersensitivity Reactions:
• Name the types of antibodies involved.
• Describe the processes which are activated.
• For each type of disorder, list the cells whose antigens are targeted:
• Transfusion reactions
• Hemolytic disease of the newborn (Rh disease)
• Insulin-dependent diabetes (Juvenile diabetes)
• Type III Hypersensitivity Reactions:
• Describe the differences in antigen-antibody complexes in Type III.
• Name the types of locations within the body where the immune complexes typically become lodged.
• List and describe two autoimmune diseases which are Type III reactions.
• List infections which involve Type III reactions.
• List drug reactions which involve Type III reactions.
• Type IV Hypersensitivity Reactions:
• List examples of contact dermatitis which are Type IV reactions.
• List types of granulomatous diseases which are Type IV reactions.

• List and/or diagram the 6 steps (links) involved in the chain of infection. List them in the order in which they occur. (Note: Must be in the correct order!)
• Give examples of how each step could be broken in a healthcare setting.
• Explain what it means to say that the goal of healthcare workers is to break this chain of infection.

• Conjugation:
  
• Describe the steps in bacterial conjugation.
• Explain what R plasmids are and why they are such a problem in healthcare.
• Describe what is different when an Hfr cross occurs during conjugation.
  
• Transduction:
  
• Define the following terms: bacteriophage (shortened to phage), productive infection, lytic phage, lytic cycle, latent state, temperate phage, prophage, lysogen, lysogenic cycle, and lysogenic conversion.
  
• Describe the process of phage infection of bacteria leading to productive infection and culminating in lysis of the bacterial cell.
• Describe the process of phage infection of bacteria leading to a latent state.
• Describe generalized transduction.
• Name bacteria and diseases associated with lysogenic conversion.
  
• Transformation:
• Describe the process of bacterial transformation.
• Explain what competency is with regard to transformation.

• Know what the "C" and the "S" in C & S Testing stand for.
• Name the common methods employed to determine the identity of a microorganism.
• Explain what kinds of information the clinician gains through culture or biochemical testing.
• Know the factors which interfere with collecting viable specimens from patients.
• Explain what serological testing involves and what it's drawback is.
• Name the common types of antibiotic sensitivity testing.
• Explain what broth dilution testing involves.
• Explain what disk dilution testing involves.