Microbiology Laboratory
Objectives

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1. List the specific hazards that one may encounter in the Microbiology Lab and describe how to protect oneself from each of those hazards.
2. Demonstrate the correct use of a compound light microscope.
3. Diagram the path of light through a compound light microscope.
4. Name and locate the major parts of a compound microscope.
5. Using prepared slides, locate and identify on oil immersion the three basic morphologies of bacteria

1. Culture and grow representative bacteria from various environments in our building.
2. Describe colonial morphology using accepted descriptive terms.
3. Compare bacterial growth on solid and liquid culture media of the bacteria isolated from the various environments.

1. Provide the rationale for aseptic technique.
2. Differentiate among the following: broth culture, agar slant, and agar deep.
3. Aseptically transfer bacteria from one form of culture medium to another.
4. Using the bacteria isolated in Exercise 9 make and fix a smear.
5. List the advantage of staining microorganisms.
6. Explain the basic mechanism of staining.
7. Perform simple direct stains using crystal violet, methylene blue, and safranin.
8. Describe the bacteria stained using oil immersion microscopy.
9. Critique your smears and simple staining techniques.

1. Explain the application and mechanism of the negative staining technique.
2. Prepare a negative stain.

1. Explain the rationale and procedure for the grarn stain.
2. Perform and interpret gram stains.

1. Using prepared slides, interpret endospore, capsule, and flagella stains.
2. Draw and describe the different flagellar arrangements.
3. Identify the functions of endospores, capsules, and flagella.

1. Identify the incubation conditions for each of the following types of organisms: aerobes, obligate anaerobes, aerotolerant anaerobes, microaerophiles, and facultative anaerobes.
2. Describe three methods of culturing anaerobes.
3. Using both reducing media and regular media in an anaerobic pouch and in aerobic conditions, separate a mixed population of bacteria from soil according to the organisms'
   preferences for atmospheric conditions.

1. Define the following: psychrophile, mesophile, and thermophile.
2. Describe the effect of temperature on the growth of bacteria.
3. Using four different pure cultures of bacteria, determine the optimum temperature for growth of each organism by subjecting each to incubation at four different temperatures: 55 degrees C, 35 degrees C, 22 degrees C, and 12 degrees C.

1. Define osmotic pressure and explain how it afffects a cell.
2. Using four different microorganisms, determine how osmotic pressure affects the growth of each organism by subjecting each to growth in increasing amounts of both NaCl and sucrose.

1. Using a mixed broth culture of several bacteria, isolate the different bacterial species from one another by using both the streak plate and the pour plate methods.
2. Prepare and maintain a pure culture from a mixed population of bacteria.

1. Differentiate between selective and differential media.
2. Provide an application for enrichment and selective media.
3. Using a mixed broth culture of a mixture of gram + and gram - bacteria, isolate each type of organism from the other using the appropriate selective media.

1. Compare the bactericidal effectiveness of dry heat and most heat on different species of bacteria
2. Evaluate the heat tolerance of certain microorganisms.
3. Define and provide a use for each of the following: incineration, hot air oven, pasteurization, boiling, and autoclaving.
4. Given a number of different microorganisms growing in broth, simulate pasteurization conditions and attempt to determine the length of time needed to completely kill each of the different microorganisms.
5. Using your data, evaluate the effectiveness of pasteurization on those organisms.

1. Perform a disk diffusion inhibition assay for disinfectants and antiseptics.
2. Accurately measure a zone of inhibition and describe the information one can get from a zone of inhibition.
3. Describe the effectiveness of the chemicals you chose to test against the organisms used in this assay.

1. Evaluate the effectiveness of handwashing using a number of different skin cleansers, including surgical soap.
2. Explain the importance of aseptic technique in the hospital environment.
3. Describe the correct length of time needed for handwashing and the appropriate soap to use in these situations: in between patients for their routine care; doing an invasive bedside procedure on a patient; preparing your hands before performing surgery.

1. Characterize and classify fungi.
2. Compare and contrast fungi and bacteria
3. Prepare cultures of and identify common saprophytic molds including Penicillium, Aspergillus, Pilobolus, Rhizopus, Alternaria, and Fusarium
4. Explain dimorphism and list the systemic dimorphic fungi and the diseases they cause.

1. Identify the morphology, staining characteristics, and probable identification of an unknown organism in pure culture.

1. Define the following terms: epidemiology, epidemic, reservoir, and carrier.
2. Describe three methods of transmission.
3. Determine the source of a simulated epidemic.

1. Isolate and identify bacteria from the human skin.
2. Provide an example of normal skin microbiota.
3. List characteristics used to identify the staphylococci.
4. Explain why many bacteria are unable to grow on human skin.

1. List representative normal microbiota of the respiratory tract.
2. Differentiate the pathogenic streptococci based on biochemical testing.
3. List a characteristic used to identify Neisseria, Corynebacterium, Mycobacterium, and Bordetella.

1. List bacteria found in urine from a healthy individual.
2. Identify, through biochemical testing, bacteria commonly associated with urinary tract infections.
3. Determine the presence or absence of Neisseria gonorrhoeae in a G.C. smear.

1. Define the following terms: antibiotic, chemotherapeutic agent, and MIC.
2. Perform an antibiotic sensitivity test.
3. Provide the rationale for the agar diffusion technique.

1. Given a culture of bacteria and a description of a patient situation from which that organism was taken, identify the organism and discuss whether or not that organism is likely to be causing that situation in that patient.
2. Determine the sensitivity of that organism to chemotherapeutic agents.