title: Molecular surveillance for carbapenemase genes in carbapenem-resistant Pseudomonas aeruginosa in Australian patients with cystic fibrosis.
abstract: The aim of this study was to assess the prevalence of acquired carbapenemase genes amongst carbapenem non-susceptible Pseudomonas aeruginosa isolates in Australian patients with cystic fibrosis (CF). Cross-sectional molecular surveillance for acquired carbapenemase genes was performed on CF P. aeruginosa isolates from two isolate banks comprising: (i) 662 carbapenem resistant P. aeruginosa isolates from 227 patients attending 10 geographically diverse Australian CF centres (2007-2009), and (ii) 519 P. aeruginosa isolates from a cohort of 173 adult patients attending one Queensland CF clinic in 2011. All 1189 P. aeruginosa isolates were tested by polymerase chain reaction (PCR) protocols targeting ten common carbapenemase genes, as well the Class 1 integron intI1 gene and the aadB aminoglycoside resistance gene. No carbapenemase genes were identified among all isolates tested. The intI1 and aadB genes were frequently detected and were significantly associated with the AUST-02 strain (OR 24.6, 95% CI 9.3-65.6; p < 0.0001) predominantly from Queensland patients. Despite the high prevalence of carbapenem resistance in P. aeruginosa in Australian patients with CF, no acquired carbapenemase genes were detected in the study, suggesting chromosomal mutations remain the key resistance mechanism in CF isolates. Systematic surveillance for carbapenemase-producing P. aeruginosa in CF by molecular surveillance is ongoing.
authors.affiliation: 1Queensland Children's Medical Research Institute, The University of Queensland, Royal Children's Hospital, Herston 2Adult Cystic Fibrosis Centre, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside 3School of Medicine, The University of Queensland, Brisbane, Qld, Australia.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Tai
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kidd
authors.forename: David M
authors.initials: DM
authors.lastname: Whiley
authors.forename: Kay A
authors.initials: KA
authors.lastname: Ramsay
authors.forename: Cameron
authors.initials: C
authors.lastname: Buckley
authors.forename: Scott C
authors.initials: SC
authors.lastname: Bell
mesh_terms: D000328:Adult; D001315:Australia; D001426:Bacterial Proteins / Q000235:genetics*; D015780:Carbapenems / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D008826:Microbial Sensitivity Tests; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D015780:Carbapenems; D004269:DNA, Bacterial; D001618:beta-Lactamases; C063912:carbapenemase