You have identified the causative organism of the outbreak as E. coli. In an effort to characterize the strain of the organism involved, you do different tests. The results are as follows:
Gram stain-Gram-negative rods; Oxidase test-negative; Lactose fermentation-positive; Serological testing-O157:H7; Colony morphology-smooth, creamy colonies; RFLPs-E. coli O157:H7; Antibiogram-resistant to ampicillin.
Which test(s) confirm the identity of the organism at the strain level?

Question

Quizplus · Accepted Answer

Serological testing (O157:H7) and RFLPs (E. coli O157:H7) both confirm the identity of the organism at the strain level. Gram stain, oxidase test, lactose fermentation, and colony morphology are all useful in identifying the genus and species of the organism, but do not provide information about the specific strain. The antibiogram does not provide information about strain identity, but does provide information about antibiotic resistance.

You Have Identified the Causative Organism of the Outbreak as E