enterocolitica

Yersinia enterocolitica is a Gram-negative, facultatively anaerobic, non-spore-forming coccobacillus in the genus Yersinia. It is a human enteric pathogen that causes yersiniosis, an infection typically presenting with diarrhea, abdominal pain, fever, and sometimes vomiting. The organism is oxidase negative and urease positive. It is motile at room temperature due to peritrichous flagella but is generally nonmotile at body temperature.

Ecology and transmission are primarily zoonotic. Y. enterocolitica is found in a variety of animals, especially pigs, and can contaminate pork products, unpasteurized milk, and contaminated water. The bacterium is notable for its ability to grow at refrigeration temperatures, enabling survival and limited replication in cold-stored foods. Transmission to humans commonly occurs via ingestion of contaminated food or water.

Clinical features range from mild gastroenteritis to more invasive disease. In otherwise healthy individuals, illness often includes abdominal pain that can mimic appendicitis, fever, and diarrhea, sometimes bloody. In children, mesenteric adenitis is observed. Immunocompromised hosts may develop bacteremia or focal infections, and reactive arthritis can follow infection.

Diagnosis relies on laboratory culture of stool or other specimens. Y. enterocolitica can be recovered on selective media such as CIN agar, where colonies may show a characteristic “bull’s-eye” appearance after cold enrichment. PCR and serology are also used in some settings.

Treatment is usually supportive, with fluids and electrolyte management. Antibiotics are reserved for severe or invasive disease and may include fluoroquinolones, trimethoprim-sulfamethoxazole, doxycycline, or third-generation cephalosporins, guided by susceptibility testing. Prevention focuses on proper cooking of pork, pasteurization of dairy products, avoidance of cross-contamination, and good hand hygiene.