You Have Identified the Causative Organism of the Outbreak as E

Multiple Choice

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?

A) Gram stain AND antibiogram
B) Serological testing AND colony morphology
C) RFLPs AND serological testing
D) Oxidase test AND RFLPs
E) Lactose fermentation AND oxidase test