Yersinia

Yersinia A family of bacteria that includes Yersinia pestis, which causes the bubonic, pneumonic, and septicemic plagues; Y. entercolitica, which causes intestinal infections, including mesenteric lymphadenitis, a condition that mimics appendicitis; and Y. pseudotuberculosis, which usually adversely affects only animals but can cause illness in immunocompromised patients. Both Y. entercolitica and Y. pseudotuberculosis have also been implicated in a viral form of arthritis. Infection with Yersinia bacteria can be treated with antibiotics. See also plague.