A microbiologist is reading stool culture plates.She is looking for enteric pathogens on the MacConkey (MAC) plate.What do they look like?
A)Clear, colorless colonies
B)Large, bright pink colonies
C)Small, mucoid, green colonies
D)Small, orange colonies

Question

Quizplus · Accepted Answer

MAC is used to differentiate lactose fermenters (bright pink) from lactose nonfermenters (clear, colorless).Most enteric pathogens do not ferment lactose.Pink colonies indicate a lactose-fermenting gram-negative rod.Green and orange colonies are not seen on MAC.

A Microbiologist Is Reading Stool Culture Plates