Yersinia enterocolitica Food Poisoning (Yersiniosis)

Yersinia enterocolitica is a type of bacteria that causes yersiniosis, a foodborne disease that affects the intestines and can lead to diarrhea, fever, and abdominal pain. It belongs to the family Yersiniaceae, which also includes Yersinia pestis, the causative agent of plague.

Yersinia enterocolitica is a gram-negative, non-spore forming bacillus or coccobacillus that can grow on common culture media. It is motile at lower temperatures (22–29 °C), but becomes nonmotile at normal human body temperature (37 °C). It is also oxidase negative, catalase positive, and facultative anaerobic.

Yersinia enterocolitica has different strains that vary in their pathogenicity and serotype. The most common serotype associated with human infection is Y. enterocolitica bioserotype 4/O:3. Some strains of Y. enterocolitica can produce a heat-stable enterotoxin (Yst) that causes fluid secretion in the intestines. Other strains have a virulence plasmid (pYV) that encodes factors for attachment, invasion, and survival within host cells.

Yersinia enterocolitica is mainly transmitted by eating raw or undercooked pork contaminated with the bacterium, but other animals such as cattle, sheep, goats, rodents, and poultry can also carry it. Vegetables, milk and milk products, water, and sewage can also be sources of contamination. The infection is more common in children than adults, and more prevalent in winter than summer.