Yersinia pseudotuberculosis

Yersinia pseudotuberculosis is a Gram-negative bacterium which primarily causes disease in animals; humans occasionally get infected zoonotically, most often through the food-borne route.

Pathogenesis
In animals, Y. pseudotuberculosis can cause tuberculosis-like symptoms, including localized tissue necrosis and granulomas in the spleen, liver, and lymph node.

In humans, symptoms are similar to those of infection with Y. enterocolitica (fever and right-sided abdominal pain), except that the diarrheal component is often absent, which sometimes makes the resulting condition difficult to diagnose. Y. pseudotuberculosis infections can mimic appendicitis, especially in children and younger adults, and, in rare cases the disease may cause skin complaints (erythema nodosum), joint stiffness and pain (reactive arthritis), or spread of bacteria to the blood (bacteremia).

Infection usually becomes apparent 5–10 days after exposure and typically lasts 1–3 weeks without treatment. In complex cases or those involving immunocompromised patients, antibiotics may be necessary for resolution; ampicillin, aminoglycosides, tetracycline, chloramphenicol, or a cephalosporin may all be effective.

The recently described syndrome Izumi-fever has been linked to infection with Y.pseudotuberculosis.