Yersinia

Yersinia
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gamma Proteobacteria
Order:	Enterobacteriales
Family:	Enterobacteriaceae
Genus:	Yersinia van Loghem, 1944
Species
Y. aldovae Y. aleksiciae Y. bercovieri Y. enterocolitica Y. frederiksenii Y. intermedia Y. kristensenii Y. mollaretii Y. pestis Y. pseudotuberculosis Y. rohdei Y. ruckeri

Yersinia is a genus of bacteria in the family Enterobacteriaceae. Yersinia are Gram-negative rod shaped bacteria, a few micrometers long and fractions of a micrometer in diameter, and are facultative anaerobes.^[1] Some members of Yersinia are pathogenic in humans; in particular, Y. pestis is the causative agent of the bubonic plague. Rodents are the natural reservoirs of Yersinia; less frequently other mammals serve as the host. Infection may occur either through blood (in the case of Y. pestis) or in an alimentary fashion, occasionally via consumption of food products (especially vegetables, milk-derived products and meat) contaminated with infected urine or feces.

Speculations exist as to whether or not certain Yersinia can also be spread via protozoonotic mechanisms, since Yersinia are known to be facultative intracellular parasites; studies and discussions of the possibility of amoeba-vectored (through the cyst form of the protozoan) Yersinia propagation and proliferation are now in progress.^[2]

Microbial physiology

An interesting feature peculiar to some of the Yersinia bacteria is the ability to not only survive but actively proliferate at temperatures as low as 1-4 degrees Celsius (e.g., on cut salads and other food products in a refrigerator). Yersinia bacteria are relatively quickly inactivated by oxidizing agents such as hydrogen peroxide and potassium permanganate solutions.

Pathogenesis

Y. pestis is the causative agent of plague. The disease caused by Y. enterocolitica is called Yersiniosis.

Y. pseudotuberculosis sometimes but rarely causes disease.^{[citation needed]}

Yersinia may be associated with Crohn's disease, an inflammatory autoimmune condition of the gut. Iranian sufferers of Crohn's disease were more likely to have had earlier exposure to refrigerators at home,^[3] consistent with Yersinia's unusual ability to thrive at low temperatures.

Yersinia is implicated as one of the causes of reactive arthritis worldwide.^[4]

History

The genus is named for A.E.J. Yersin, a Swiss bacteriologist, who discovered the Yersinia pestis bacterium—the causative agent of the bubonic plague. The special genus Yersinia has been recognized since 1971, mainly for taxonomic reasons.^{[citation needed]}

References

External links

• Yersinia Enterocolitis Mimicking Crohn's Disease in a Toddler
• Sweden: Pork warnings over new stomach illness
• Genomic information on Yersinia is available at ERIC