Question

Scientists from the CDC were tracking a series of sick individuals in more than a dozen states who all displayed vomiting and diarrhea typically associated with salmonellosis. Two weeks after the initial outbreak another 27 cases of the infection stretching across a total of 14 states was being tracked. Within four months more than 600 people had become infected from 46 states and Canada and 9 of the victims had died.

In order to determine if the illness was indeed salmonellosis, microbiologists streaked samples obtained from the patients on a Hektoen Enteric Agar. This agar contains bile salts which inhibit the growth of gram⁺ bacteria. Further, there are three different carbohydrates and ammonium citrate and sodium thiosulfate are also in the in the agar that help to distinguish between groups of bacteria.

When looking at Hektoen Enteric Agar, the addition of bile salt allows the media to be -

A. selective media

B. differential media

C. micronutrient media

D. growth factor containing media

E. rich media

Answer 1

Answer selective media because bile salt inhibits the growth of all gram positive bacteria and media selectively favors for Salmonella