''Yersinia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

in the family

Yersiniaceae The Yersiniaceae are a family of Gram-negative bacteria that includes some familiar pathogens. For example, the type genus ''Yersinia'' includes ''Yersinia pestis'', the causative agent of plague. This family is a member of the order Enterobacter ...

. ''Yersinia'' species are

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

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 ...

, a few micrometers long and fractions of a micrometer in diameter, and are

facultative anaerobe A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent. Some examples of facultatively anaerobic bacteria are '' Staphylococ ...

s. 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 ...

Rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

s are the natural reservoirs of ''Yersinia''; less frequently, other

mammals Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur o ...

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 Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...

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 rela ...

. 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

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson h ...

s; studies and discussions of the possibility of

amoeba An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudop ...

-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 agent An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...

s such as

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ...

and

potassium permanganate Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution. Potassium permanganate is widely used in the c ...

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 The University of Malaya ( ms, Universiti Malaya, UM; abbreviated as UM or informally the Malayan University) is a public research university located in Kuala Lumpur, Malaysia. It is the oldest and highest ranking Malaysian institution of highe ...

and the Ministry of Education, Malaysia.

Pathogenesis

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

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

, 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 Reactive arthritis, also known as Reiter's syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infection can t ...

worldwide. Also, the genus is associated with pseudoappendicitis, 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 A bacteriologist is a microbiologist, or similarly trained professional, in bacteriology -- a subdivision of microbiology that studies bacteria, typically pathogenic ones. Bacteriologists are interested in studying and learning about bacteria, ...

, 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 nominat ...

, 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