When these Yersinia organisms are present in normally sterile tissue or normally sterile secretions, such as blood or cerebrospinal fluid, they grow well on routine media, but isolation from feces remains a challenge. Yersinia species grow more slowly than other Enterobacteriaceae at 37 C and are quickly overgrown on culture plates. Also, it is difficult to distinguish Yersinia colonies from those of other Enterobacteriaceae because they share a very similar morphology. Full recognition of the impact of Yersinia infection must await the development of simpler isolation methods, just as complete awareness of the importance of Campylo bacter infection came only after the development of special selective media for that organism. Serologic tests are available for the diagnosis of Yersinia infection.
Antibody titers peak one to two weeks after the onset of clinical disease.
Although direct data are not available, antiperistaltic agents should not be used to treat Y. enterocolitica or Y. pseudotuberculosis disease. The efficacy of antibiotics in the treatment of patients with enterocolitis or mesenteric adenitis, or both, has not been established. Septicemia definitely must be treated. Ampicillin, streptomycin, or tetracycline is recommended for Y. pseudotu berculosis septicemia. For patients who are excreting either of these Yer sinia species, strict enteric precautions are clearly indicated.