''Shimwellia'' 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 n ...

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 ...

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 ...

of the family

Enterobacteriaceae Enterobacteriaceae is a large family of Gram-negative bacteria. It was first proposed by Rahn in 1936, and now includes over 30 genera and more than 100 species. Its classification above the level of family is still a subject of debate, but on ...

. The two species of ''Shimwellia'' are ''

Shimwellia blattae ''Shimwellia blattae'' (formerly ''Escherichia blattae'') is a species of bacterium, one of two in the genus '' Shimwellia''. It is an aerobic enteric bacterium first isolated from the hindgut of cockroaches. Although it is related to human pat ...

'' (formerly ''Escherichia blattae'') and '' Shimwellia pseudoproteus'' (formerly ''Obesumbacterium pseudoproteus''). Species in ''Shimwellia'' are genetically similar to ''Escherichia'' but differ in notable ways. ''S. blattae'' can synthesize

coenzyme B12 Cyanocobalamin is a form of vitamin used to treat vitamin deficiency except in the presence of cyanide toxicity. The deficiency may occur in pernicious anemia, following surgical removal of the stomach, with fish tapeworm, or due to bowel c ...

and ''S. pseudoproteus'' is associated with beer spoilage.

References

Gram-negative bacteria Bacteria genera {{Enterobacterales-stub