''Shimwellia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 wall ...

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 among ...

of the family

Enterobacteriaceae Enterobacteriaceae is a large family (biology), 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 ...

. The two species of ''Shimwellia'' are '' Shimwellia blattae'' (formerly ''Escherichia blattae'') and ''

Shimwellia pseudoproteus ''Shimwellia'' is a genus of Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Shimwellia'' are ''Shimwellia blattae'' (formerly ''Escherichia blattae'') and ''Shimwellia pseudoproteus'' (formerly ''Obesumbacterium ps ...

'' (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 ...

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

References

Gram-negative bacteria Bacteria genera {{Enterobacterales-stub