What term describes the number of colonies that form distinctive countable colonies on Violet Red Bile Agar after 24 hours at 32°C?

What term describes the number of colonies that form distinctive countable colonies on Violet Red Bile Agar after 24 hours at 32°C?

• A. Viable Count
• B. Bacteria Count
• C. Coliform Count
• D. Somatic Cell Count

Answer: (C)

The key idea is identifying a specific group of indicator bacteria on a selective medium. Violet Red Bile Agar is designed to isolate and differentiate coliforms, which are lactose-fermenting bacteria that produce characteristic colonies after incubation. Counting the colonies that meet this typical appearance after 24 hours at 32°C gives the Coliform Count. This value serves as an index of sanitary quality and potential contamination in dairy products. A viable count would include all living organisms able to grow under those conditions, not just coliforms, so it’s not specific. A bacteria count is too general and doesn’t indicate which group is being counted. Somatic cell count relates to milk quality and mammary health, not microbial enumeration.

The key idea is identifying a specific group of indicator bacteria on a selective medium. Violet Red Bile Agar is designed to isolate and differentiate coliforms, which are lactose-fermenting bacteria that produce characteristic colonies after incubation. Counting the colonies that meet this typical appearance after 24 hours at 32°C gives the Coliform Count. This value serves as an index of sanitary quality and potential contamination in dairy products.

A viable count would include all living organisms able to grow under those conditions, not just coliforms, so it’s not specific. A bacteria count is too general and doesn’t indicate which group is being counted. Somatic cell count relates to milk quality and mammary health, not microbial enumeration.