Yersinia enterocolitica are the bacteria that cause yersiniosis. The major animal reservoir for the strains that cause human illness is pigs. Other possible animal carriers include rodents, sheep, and cattle. Symptoms of infection can vary, depending on the age of the person infected; however, fever and abdominal pain are the most common. Most cases are uncomplicated and resolve completely.
Yersinia enterocolitica are a type of Gram-negative bacteria that cause yersiniosis. Although the bacteria are primarily found in northern Europe and North America, worldwide, they are responsible for 1 to 3 percent of diarrhea illnesses.
Yersinia enterocolitica were formerly classified in the Pasteurellaceae family, but based on their similarities to Escherichia coli (E. coli), the Yersinia group has been reclassified as members of the Enterobacteriaceae family.
Although there are 11 named species in the genus Yersinia, only three are considered important human pathogens:
Yersinia pseudotuberculosis is the closest genetic relative to Yersinia pestis, but can be distinguished from it by the symptoms it causes and by laboratory test results.
Neither Yersinia pestis nor Yersinia pseudotuberculosis frequently infect humans, in contrast to Yersinia enterocolitica, which, as mentioned, accounts for 1 to 3 percent of bacterial-related diarrhea cases.