The description is based on Grimont and Grimont (2005), Hoffmann et al. (2005), Zhu et al. (2011), Manter et al. (2011) [18], [19], [22], [23], [36], [56] and this study. Cells are straight rods, 0.6–1.2 μm × 1.2–3.0 μm, motile by peritrichous flagella. Gram negative. Facultatively anaerobic. Optimum temperature for growth is 30 °C, most clinical strains grow at 37 °C but some environmental strains give erratic biochemical reactions at 37 °C. Growth occurs readily on ordinary media and colonies are cream, round, convex and smooth with entire margins. The majority are positive for Voges-Proskauer, arginine dihydrolase and ornithine decarboxylase, and negative for indole, lysine decarboxylase and H2S production. Nitrate is reduced to nitrite. Glucose is fermented with production of acid and gas. N-acetyl-d-glucosamine, l-arabinose, d-cellobiose, d-galactose, maltose, d-mannitol, d-mannose, d-trehalose, cis-aconitic acid, d-gluconic acid, glycerol, α-d-glucose-1-phosphate, d-glucose-6-phosphate are used oxidized (Biolog), whereas itaconic acid, propionic acid, 2-aminoethanol and 2,3-butanediol are not. Reactions to tweens 40 and 80, N-acetyl-d-galactosamine, d-arabitol, d-fructose, gentiobiose, d-glucose, m-inositol, lactose, d-melibiose, d-raffinose, l-rhamnose, d-sorbitol, sucrose, turanose, succinic acid mono-methyl ester, p-hydroxy-phenylacetic acid, d-saccharic acid, l-alaninamide, l-proline, d-serine and l-threonine are variable. Major fatty acids are C16:0, C18:1ω7c, C17:0 cyclo and summed feature 2 (iso-C16:1 and/or C14:0 3-OH). The fatty acids C13:0 and summed feature 1 (C15:1 iso H and/or C13:0 3-OH) are generally present in low amounts (minimum 1.4 and 1.6% of the total amount, respectively). Members of the genus Enterobacter form a clade using MLSA based on concatenated partial gyrB, rpoB, infB and atpD sequences.

Enterobacter species are widely distributed in nature and have been isolated from humans, animals, clinical samples, plants and the natural environment.

The type species is Enterobacter cloacae (Jordan 1890) Hormaeche and Edwards 1960.