The genus Yersinia fits into the family of the Enterobacteriaceae. Along with the human pathogens Y. enterocolitica, Y. pestis and Y. pseudotuberculosis, it comprises other non-pathogenic species. Yersiniae takes place globally in temperate and subtropical climates. The most significant bacterial reservoirs for Y. enterocolitica and Y. pseudotuberculosis, the causes of enteric yersiniosis, are latent infections in the warm-blooded wild, working and domestic animals especially in domestic pigs, whose excreta lead to infectivity of the environment. Diffusion to humans is mainly alimentary. Y. enterocolitica infections are evident after an incubation period of approximately 14 days mainly as mesenteric lymphadenitis, which presents clinically as enteritis, pseudo appendicitis, ileitis or colitis.