You are working in a clinical lab. Two E. coli samples are sent to you for analysis and you are asked to determined whether they are the same strain. You perform an antibiogram and find that the two samples exhibit the same sensitivity to the antibiotics you use in the procedure. This indicates
A) the organisms are likely the same strain but you need to confirm this with other methods.
B) the organisms are likely different strains but you need to confirm this with other methods.
C) the two organisms are not likely to be susceptible to the same bacteriophages.
D) the two organisms will show different results if they are Gram stained.
E) the organisms are the same strains but they will react differently in serology tests.

Question

You are working in a clinical lab. Two E. coli samples are sent to you for analysis and you are asked to determined whether they are the same strain. You perform an antibiogram and find that the two samples exhibit the same sensitivity to the antibiotics you use in the procedure. This indicates
A) the organisms are likely the same strain but you need to confirm this with other methods.
B) the organisms are likely different strains but you need to confirm this with other methods.
C) the two organisms are not likely to be susceptible to the same bacteriophages.
D) the two organisms will show different results if they are Gram stained.
E) the organisms are the same strains but they will react differently in serology tests.

Quizplus · Accepted Answer

Antibiotic sensitivity is a useful tool for distinguishing bacterial strains, but it is not definitive. The fact that these two samples exhibit the same sensitivity suggests that they may be the same strain, but additional tests (such as DNA fingerprinting) would be needed to confirm this. Option B is incorrect because, as mentioned, the antibiotic sensitivity results suggest that the strains may be the same. Option C is incorrect because bacteriophage susceptibility is not related to antibiotic sensitivity. Option D is incorrect because Gram staining results would not be useful for determining if strains are the same or different. Option E is also incorrect because serological tests measure different aspects of bacterial cells than antibiotic sensitivity tests, and there is no reason to predict that the two strains would react differently in these tests.

You Are Working in a Clinical Lab