Bacteria: Yersinia enterocolitica and Yersinia pseudotuberculosis

There are three pathogenic Yersinia species: enterocolitica , pseudotuberculosis , and pestis . Only the first two are of concern as foodborne disease, and not all strains are pathogenic to humans. Although Yersinia infections are not frequently encountered, they are important zoonotic foodborne pathogens, particularly in temperate regions. Symptoms are mainly gastrointestinal, often with severe abdominal pain resembling appendicitis, but the invasive organisms can extend the duration of illness through postenteric sequelae like reactive arthritis and/or erythema nodosum. Implicated food vehicles have been unpasteurized milk, untreated water, chocolate milk, and tofu ( Y. enterocolitica ), and lettuce, carrots, and pasteurized milk ( Y. pseudotuberculosis ).