Escherichia

Escherichia (/ˌɛʃəˈrɪkiə/ ESH-ə-RIK-ee-ə) is a genus of Gram-negative, non-spore-forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae.^[3] In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, Escherichia species provide a portion of the microbially derived vitamin K for their host. A number of the species of Escherichia are pathogenic.^[4] The genus is named after Theodor Escherich, the discoverer of Escherichia coli. Escherichia are facultative aerobes, with both aerobic and anaerobic growth, and an optimum temperature of 37 °C.^[3] Escherichia are usually motile by flagella, produce gas from fermentable carbohydrates, and do not decarboxylate lysine or hydrolyze arginine.^[5] Species include E. albertii, E. fergusonii, E. hermannii, E. ruysiae, E. marmotae and most notably, the model organism and clinically relevant E. coli. Formerly, Shimwellia blattae^[6] and Pseudescherichia vulneris were also classified in this genus.

Escherichia
SEM micrograph of cluster of Escherichia coli bacteria. Each individual bacterium is oblong.
Scientific classification
Domain:	Bacteria
Kingdom:	Pseudomonadati
Phylum:	Pseudomonadota
Class:	Gammaproteobacteria
Order:	Enterobacterales
Family:	Enterobacteriaceae
Tribe:	Escherichieae
Genus:	Escherichia Castellani & Chalmers 1919[1]
Type species
Escherichia coli (Escherich, 1886)
Species
E. albertii E. coli E. fergusonii E. hermannii E. ruysiae[2] E. marmotae[2]

Pathogenesis

While many Escherichia are commensal members of the gut microbiota, certain strains of some species, most notably the pathogenic serotypes of E. coli, are human pathogens,^[7] and are the most common cause of urinary tract infections,^[8] significant sources of gastrointestinal disease, ranging from simple diarrhea to dysentery-like conditions,^[3] as well as a wide range of other pathogenic states^[9] classifiable in general as colonic escherichiosis. While E. coli is responsible for the vast majority of Escherichia-related pathogenesis, other members of the genus have also been implicated in human disease.^[10][11] Escherichia are associated with the imbalance of microbiota of the lower reproductive tract of women. These species are associated with inflammation.^[12]

See also

• E. coli O157:H7
• List of bacterial genera named after personal names