Which medias are differential?

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Multiple Choice

Which medias are differential?

Differential media reveal differences between organisms based on their metabolism or biochemical properties, producing visible changes in colonies, colors, or surrounding media. MacConkey agar differentiates Gram-negative bacteria by lactose fermentation: lactose fermenters turn pink or red due to the acid produced, while non-fermenters remain colorless. Hektoen enteric agar differentiates enteric bacteria by lactose/sucrose fermentation and hydrogen sulfide production; fermenters show color changes in the colonies, and H2S producers develop black centers. Blood agar is differential for hemolysis: beta-hemolysis clears around colonies, alpha-hemolysis yields a greenish zone, and gamma-hemolysis shows no change, all while providing enriched growth. Chocolate agar is primarily an enriched medium to grow fastidious organisms and is not used for differential testing in the same way, while Thayer-Martin–type media are selective rather than differential. Thus, MAC, HEK, and BAP are the differential media in the set.

Differential media reveal differences between organisms based on their metabolism or biochemical properties, producing visible changes in colonies, colors, or surrounding media.

MacConkey agar differentiates Gram-negative bacteria by lactose fermentation: lactose fermenters turn pink or red due to the acid produced, while non-fermenters remain colorless. Hektoen enteric agar differentiates enteric bacteria by lactose/sucrose fermentation and hydrogen sulfide production; fermenters show color changes in the colonies, and H2S producers develop black centers. Blood agar is differential for hemolysis: beta-hemolysis clears around colonies, alpha-hemolysis yields a greenish zone, and gamma-hemolysis shows no change, all while providing enriched growth.

Chocolate agar is primarily an enriched medium to grow fastidious organisms and is not used for differential testing in the same way, while Thayer-Martin–type media are selective rather than differential.

Thus, MAC, HEK, and BAP are the differential media in the set.

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