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The Lab Exercises have been created over many years as a team effort by the Molecular Biology and Microbiology faculty.

1. Date and Time:

Fall 2004, 1 hour

2. Part D Fecal flora

2.1. Special Materials:

Rulers and examples of fermentation tubes.

2.2. Procedure:

Prepare a short summary of your results indicating the frequency of Tetr and Ampr Lac+ bacteria in your fecal sample, and the antibiotic sensitivity and fermentation properties of your Lac+ clone. Note which sugars your samples could ferment and where the bacteria are growing in the tube.

Some fermentation patterns of gram-negative bacteria normally isolated from fecal flora and gram-negative pathogens. Note: some of the normal fecal flora can cause disease if they colonize other sites in the body.

Normal fecal flora Glucose Lactose Maltose
E. coli + + +
Proteus (swarming)
mirabilis
vulgaris

+
+

-
-

-
+
Klebsiella (highly capsulated) + + +
Citrobacter freudii + 50% of strains are positive +
Pathogens Glucose Lactose Maltose
Salmonella + - +
Shigella + - 30% are positive
Vibrio
(curved or spiral, not a rod)
+ + +
Camphylobacter
(curved or spiral, not a rod)

2.3. Discussion of all lab experiments and results

Once the class has completed Part D, we will discuss the types of bacteria isolated by the class, and the frequency of antibiotic resistance.

3. HAND IN ALL REPORTS. (last page of lab manual)

PUT AWAY EVERYTHING AND CLEAN BENCHES AND THEN YOUR HANDS!!!