title: Distribution of intrinsic plasmid replicase genes and their association with carbapenem-hydrolyzing class D beta-lactamase genes in European clinical isolates of Acinetobacter baumannii.
abstract: Ninety-six genetically diverse multidrug-resistant clinical isolates of Acinetobacter baumannii from 25 hospitals in 17 European countries were screened by PCR for specific carbapenemase-hydrolyzing class D β-lactamase (CHDL) genes and by PCR-based replicon typing for the presence of 19 different plasmid replicase (rep) gene homology groups (GRs). Results were confirmed by DNA sequencing where necessary. All 96 isolates contained at least 1 (with a maximum of 4) of the 19 groups of rep genes. Groups detected were GR6 (repAci6; 93 isolates), GR2 (including repAci1 [67 isolates] and repAci2 [3 isolates]), GR16 (repApAB49; 12 isolates), GR12 (p2ABSDF0001; 10 isolates), GR3 (repAci3; 4 isolates), GR4 (repAci4; 3 isolates), GR10 (repAciX; 1 isolate), and GR14 (repp4AYE; 1 isolate). Variations in rep gene content were observed even among epidemiologically related isolates. Genes encoding OXA-58-like CHDLs (22 isolates) were associated with carriage of the repAci1, repAci3, repAci4, and repAciX genes, genes encoding OXA-40-like CHDLs (6 isolates) were associated with repAci2 and p2ABSDF0001, and genes encoding OXA-23-like CHDLs (8 isolates) were associated with repAci1. Most intrinsic Acinetobacter plasmids are non-self-transferable, but the almost ubiquitous repAci6 gene was strongly associated with a potential tra locus that could serve as a general system for plasmid mobilization and consequent horizontal transmission of plasmids and their associated antibiotic resistance genes among strains of A. baumannii.
authors.affiliation: Department of Clinical Microbiology, Nottingham University Hospitals NHS Trust, 70 Newstead Drive, West Bridgford, Nottingham NG2 6LG, United Kingdom. Kevin.Towner@btinternet.com
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Towner
authors.forename: Benjamin
authors.initials: B
authors.lastname: Evans
authors.forename: Laura
authors.initials: L
authors.lastname: Villa
authors.forename: Katrina
authors.initials: K
authors.lastname: Levi
authors.forename: Ahmed
authors.initials: A
authors.lastname: Hamouda
authors.forename: Sebastian G B
authors.initials: SG
authors.lastname: Amyes
authors.forename: Alessandra
authors.initials: A
authors.lastname: Carattoli
mesh_terms: D040981:Acinetobacter baumannii / Q000201:enzymology* / Q000235:genetics*; D015780:Carbapenems / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D015780:Carbapenems; D001618:beta-Lactamases