MADISON AREA TECHNICAL COLLEGE
CLINICAL LABORATORY TECHNICIAN PROGRAM
Clinical Microbiology 513-111
Week 5 Laboratory 1

Comparison Worksheet for E.coli and 
Contaminated Urine Culture Plates

For the urine culture with E.coli:

  1. Is there more than one organism growing on the plates?

 

  1. Would you report the colony count as greater than 105 CFU/ml, 104 -105 CFU/ml or less than 104 CFU/ml?

 

  1. What urinalysis dipstick results would you expect to be positive?

 

Please identify the contaminated urine plates by their lab#.

1.  What are the colony counts for each of these cultures?

 

2.  Do these plates have gram-positive or gram-negative organisms?

 

3.  Describe the different colony types present for each urine culture. Use the lab # for identification

 

4.  Lactobacilli, a common vaginal contaminant, are small, alpha-hemolytic colonies, are these present on any of the culture plates?

If so, which ones? 

What is the catalase reaction for lactobacilli?

5.  Are there any white, shiny, opaque colonies that look like Staphylococcus epidermidis?

If so, which ones? 

What is their catalase reaction?

 

6.  Are there any colonies that look like Corynebacterium species (diphtheroids)?

If so, which ones?

7.  Are there any colonies that look like yeast? 

If so, which ones?

8.  Are there any beta-hemolytic colonies on any of the contaminated urine culture plates?

If so, so they look more like Staphylococcus aureus and  Streptococcus agalactiae?

 

9. Consult pages 216, 1018-1019 of your text and list common urinary contaminants due to skin and urogenital normal flora organisms.

 

 

 

 

 

Clinical Microbiology Syllabus