Gram-negative, strictly aerobic, non-fermenting, non-fastidious, non-motile, catalase-positive, oxidase-negative bacteria with a DNA G + C content of 39% to 47%
33 valid species and 10 provisional species based on DNA–DNA hybridization, all of which encompass strains found in a wide range of ecological niches
The most medically relevant species belong to the A. baumannii complex, which includes A. baumannii, A. pitti sp. nov. and A. nosocomialis sp. nov.
A. baumannii has been designated as a “red alert” human pathogen, because of its extensive antibiotic resistance spectrum
Genomic analysis confirms the multifactorial and combinatorial nature of A. baumannii virulence, with no unique virulence factor being identified yet.
A. baumannii is an emerging opportunistic bacterial pathogen primarily associated with hospital-acquired infections including pneumonia (both hospital and community acquired), bacteremia, endocarditis, skin and soft tissue infections, urinary tract infections, and meningitis.
Genomes (comparative pathogenomics):
A. baumannii 1656-2, 3940614 bp, NC_017162
A. baumannii AB0057, 4050513 bp, NC_011586
A. baumannii AB307-0294, 3760981 bp, NC_011595
A. baumannii ACICU, 3904116 bp, NC_010611
A. baumannii ATCC 17978, 3976747 bp, NC_009085
A. baumannii AYE, 3936291 bp, NC_010410
A. baumannii BJAB07104, 3951920 bp, NC_021726
A. baumannii BJAB0715, 4001621 bp, NC_021733
A. baumannii BJAB0868, 3906795 bp, NC_021729
A. baumannii D1279779, 3704285 bp, NC_020547
A. baumannii MDR-TJ, 3964912 bp, NC_017847
A. baumannii MDR-ZJ06, 3991133 bp, NC_017171
A. baumannii SDF, 3421954 bp, NC_010400
A. baumannii TCDC-AB0715, 4138388 bp, NC_017387
A. baumannii TYTH-1, 3957368 bp, NC_018706
Park JY, et al., 2011. Complete genome sequence of multidrug-resistant Acinetobacter baumannii strain 1656-2, which forms sturdy biofilm. J Bacteriol 193(22):6393-6394.
Adams MD, et al., 2008. Comparative genome sequence analysis of multidrug-resistant Acinetobacter baumannii. J Bacteriol 190(24):8053-8064.
Iacono M, et al., 2008. Whole-genome pyrosequencing of an epidemic multidrug-resistant Acinetobacter baumannii strain belonging to the European clone II group. Antimicrob Agents Chemother 52(7):2616-2625.
Smith MG, et al., 2007. New insights into Acinetobacter baumannii pathogenesis revealed by high-density pyrosequencing and transposon mutagenesis. Genes Dev 21(5):601-614.
Vallenet D, et al., 2008. Comparative analysis of Acinetobacters: three genomes for three lifestyles. PLoS One 3(3):e1805.
Zhu L, et al., 2013. Complete genome analysis of three Acinetobacter baumannii clinical isolates in China for insight into the diversification of drug resistance elements. PLoS One 8(6):e66584.
Farrugia DN, et al., 2013. The complete genome and phenome of a community-acquired Acinetobacter baumannii. PLoS One 8(3):e58628.
Huang H, et al., 2012. Complete genome sequence of Acinetobacter baumannii MDR-TJ and insights into its mechanism of antibiotic resistance. J Antimicrob Chemother 67(12):2825-2832.
Chen CC, et al., 2011. Genome sequence of a dominant, multidrug-resistant Acinetobacter baumannii strain, TCDC-AB0715. J Bacteriol 193(9):2361-2362.
Liou ML, et al., 2012. Genome sequence of Acinetobacter baumannii TYTH-1. J Bacteriol 194(24):6974.
Major virulence factors in Acinetobacter:
AdeFGH efflux pump
Location of virulence-associated genes in A. baumannii: