A.ci.ne.to.bac'ter. Gr. masc. adj. akinetos unable to move; N.L. masc. adj. bacter, a rod; N.L. masc. n. Acinetobacter, a non-motile rod.
Proteobacteria / Gammaproteobacteria / Pseudomonadales / Moraxellaceae / Acinetobacter
Rods 0.9-1.6 x 1.5-2.5 μm, becoming spherical in the stationary phase of growth. Colonies are generally nonpigmented and are mucoid when the cells are encapsulated. Cells commonly occur in pairs. Do not form spores. Gram-stain-negative. Flagella are absent, and swimming motility does not occur, but cells display twitching motility associated with fimbriae. Strictly aerobic. Oxidase-negative. Catalase-positive. Mesophilic. Most strains do not reduce nitrate to nitrite in conventional assays. Grow well on complex media. Most strains grow in defined media containing a single carbon and energy source (most commonly acetate), using ammonium or nitrate salts or one of several common amino acids, as a source of nitrogen. The genome consists of a single circular chromosome sized 2.6-4.7 Mb and a strain-dependent set of plasmid replicons. Widespread in nature, inhabiting diverse soil and water ecosystems and being associated with plants and animals. Some species reside on the human skin and mucosa. Several species can cause nosocomial infections; strains involved are often resistant to multiple antibiotics and can give rise to epidemics. In 2021, the genus included 73 species with correct names.
DNA G + C content (mol%): 34.9-49.6 (median: 40.2).
Type species: Acinetobacter calcoaceticus Baumann et al. 1968bAL (basonym: Micrococcus calcoaceticus Beijerinck 1911) emend. Bouvet and Grimont 1986.