Which set of media is used for stool cultures to detect a range of gastrointestinal organisms?

Prepare for the CAMLPR Microbiology Test. Utilize flashcards and engaging multiple-choice questions, each equipped with descriptions and explanations. Ready yourself for an excellent performance!

Multiple Choice

Which set of media is used for stool cultures to detect a range of gastrointestinal organisms?

Stool cultures aim to recover a broad spectrum of enteric pathogens, so a panel of selective and differential media is used together. This combination includes Hektoen enteric agar, which helps distinguish Salmonella and Shigella from other enterics based on colony color and H2S production; MacConkey agar, which separates lactose fermenters from non-fermenters; SMAC (sorbitol-MacConkey), which screens for the absence of sorbitol fermentation typical of E. coli O157:H7; and CIN agar, which is selective for Yersinia species and often shows the characteristic bull’s-eye colonies. Using these together covers a wide range of common gastrointestinal pathogens more effectively than any single medium. The other options lack this broad coverage: a general blood agar or chocolate agar alone isn’t selective for enteric pathogens; using MacConkey alone misses some organisms that the differential media help identify; and relying on a single medium would not detect the full spectrum of potential GI pathogens.

Stool cultures aim to recover a broad spectrum of enteric pathogens, so a panel of selective and differential media is used together. This combination includes Hektoen enteric agar, which helps distinguish Salmonella and Shigella from other enterics based on colony color and H2S production; MacConkey agar, which separates lactose fermenters from non-fermenters; SMAC (sorbitol-MacConkey), which screens for the absence of sorbitol fermentation typical of E. coli O157:H7; and CIN agar, which is selective for Yersinia species and often shows the characteristic bull’s-eye colonies. Using these together covers a wide range of common gastrointestinal pathogens more effectively than any single medium.

The other options lack this broad coverage: a general blood agar or chocolate agar alone isn’t selective for enteric pathogens; using MacConkey alone misses some organisms that the differential media help identify; and relying on a single medium would not detect the full spectrum of potential GI pathogens.

More practice questions