Which organism's recovery is enhanced by cold enrichment of feces in phosphate-buffered saline?

The recovery of Yersinia enterocolitica is enhanced by cold enrichment of feces in phosphate-buffered saline due to the unique characteristics of this bacterium and its ecological niche. Yersinia enterocolitica is known to thrive in colder temperatures, which is why the method of cold enrichment is effective. The temperature around 4°C is not only conducive to the growth of Yersinia but also helps suppress the growth of other competing flora, allowing for a more selective isolation process.

During the cold enrichment process, the phosphate-buffered saline provides a stable environment that maintains pH and protects the viability of the bacteria, facilitating their growth when incubated at lower temperatures. This method is typically used because Yersinia enterocolitica can be difficult to isolate from fecal samples, and cold enrichment increases the likelihood of detection in laboratory settings.

While other options may also be significant pathogens, they do not share the same enhancement of recovery through cold enrichment. For example, Enterotoxigenic E. coli is generally detected using enriched media at higher temperatures, while Salmonella paratyphi and Hafnia alvei are not specifically benefited from cold enrichment as Yersinia enterocolitica is. This specificity in the growth conditions underscores why