What growth characteristic aids the detection of Yersinia enterocolitica in clinical specimens?

• A. Growth at cold temperatures (cold enrichment)
• B. Growth only at high temperatures
• C. Requirement for high-salt media
• D. Growth in anaerobic conditions

Answer: (D)

Cold growth at refrigeration temperatures is the trait that aids detection. Yersinia enterocolitica can multiply at about 4°C, a property called psychrotolerance. By incubating clinical specimens at this cold temperature (cold enrichment), Yersinia is selectively enriched because many other gut bacteria don’t grow well or at all at that temperature. After cold enrichment, the organism is then recovered on selective media, making it easier to identify. While Yersinia is a facultative anaerobe and can grow without oxygen, that trait isn’t what makes it easier to detect in this context, and high-salt growth requirements aren’t characteristic tools for its routine detection.