''Yersinia'' is a genus of bacteria in the family Yersiniaceae. ''Yersinia'' species are Gram-negative,

coccobacilli A coccobacillus (plural coccobacilli), or bacilluscocco, is a type of bacterium with a shape intermediate between cocci (spherical bacteria) and bacilli (rod-shaped bacteria). Coccobacilli, then, are very short rods which may be mistaken for cocci ...

bacteria, a few micrometers long and fractions of a micrometer in diameter, and are facultative anaerobes. Some members of ''Yersinia'' are pathogenic in humans; in particular, '' Y. pestis'' is the causative agent of the

plague Plague or The Plague may refer to: Agriculture, fauna, and medicine *Plague (disease), a disease caused by ''Yersinia pestis'' * An epidemic of infectious disease (medical or agricultural) * A pandemic caused by such a disease * A swarm of pes ...

. Rodents are the natural reservoirs of ''Yersinia''; less frequently, other mammals serve as the

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel 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 Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...

. Speculations exist as to whether or not certain ''Yersinia'' can also be spread by protozoonotic mechanisms, since ''Yersinia'' species 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.

Microbial physiology

An interesting feature peculiar to some of the ''Yersinia'' bacteria is the ability to not only survive, but also to actively proliferate at temperatures as low as 1–4 °C (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.

Genetics

Database

The creation of YersiniaBase, a data and tools collection for the reporting and comparison of ''Yersinia'' species genome sequence data, was reported in January 2015. The provisional representation of species addressed by the resource has been indicated in the TaxBox on this page by a superscript 'yb' beside the species name. Development of YersiniaBase was funded by the University of Malaya and the Ministry of Education, Malaysia.

Pathogenesis

''Y. pestis'' is the causative agent of

. The disease caused by '' Y. enterocolitica'' is called

yersiniosis Yersiniosis is an infectious disease caused by a bacterium of the genus ''Yersinia''. In the United States, most yersiniosis infections among humans are caused by ''Yersinia enterocolitica''. Infection with '' Y. enterocolitica'' occurs most o ...

. ''Yersinia'' may be associated with

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension ...

, 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, consistent with its unusual ability to thrive at low temperatures. ''Yersinia'' is implicated as one of the causes of reactive arthritis worldwide. Also, the genus is associated with

pseudoappendicitis Appendicitis is inflammation of the appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, and decreased appetite. However, approximately 40% of people do not have these typical symptoms. Severe complications of a rupt ...

, which is an incorrect diagnosis of appendicitis due to a similar presentation.

History

''Y. pestis'', the first known species, was identified in 1894 by A.E.J. Yersin, a Swiss bacteriologist, and

Kitasato Shibasaburō Baron was a Japanese physician and bacteriologist. He is remembered as the co-discoverer of the infectious agent of bubonic plague in Hong Kong during an outbreak in 1894, almost simultaneously with Alexandre Yersin. Kitasato was nominated ...

, a Japanese bacteriologist. It was formerly described as '' Pasteurella pestis'' (known trivially as the plague-bacillus) by Lehmann and Neumann in 1896. In 1944, van Loghem reclassified the species ''P. pestis'' and ''P. rondentium'' into a new genus, ''Yersinia''. Following the introduction of the bacteriological code, it was accepted as valid in 1980.

References

External links

''Yersinia'' Enterocolitis Mimicking Crohn's Disease in a ToddlerSweden: Pork warnings over new stomach illness

''Yersinia''
genomes and related information a
PATRIC
a Bioinformatics Resource Center funded b
NIAID
* {{Taxonbar, from=Q132231 Bacteria genera