title: ISPa46, a novel insertion sequence in the oprD porin gene of an imipenem-resistant Pseudomonas aeruginosa isolate from a cystic fibrosis patient in Marseille, France.
abstract: Clinical isolates of Pseudomonas aeruginosa exhibiting high-level resistance to carbapenems were recovered from a French patient with cystic fibrosis (CF) who had not received carbapenem therapy. This study was conducted to investigate the molecular mechanism conferring the carbapenem-resistant phenotype in clinical isolates of P. aeruginosa recovered from the same CF patient chronically colonised since 2005. Investigation of imipenem resistance of P. aeruginosa strain_02 isolated in May 2011 showed no carbapenemase activity. However, amplification and sequencing of the oprD porin gene revealed disruption of this gene by an insertion sequence (IS) element of 1337 bp that contained a novel transposase of 1227 bp (ISPa46) bordered by two terminal imperfect inverted repeats of 28 bp, which was associated with carbapenem resistance. Retrospective analysis of five additional strains of P. aeruginosa isolated before May 2011 from the same patient revealed that all isolates were likely to be the same clone by multilocus sequence typing analysis (ST540/551), but one of the five isolates was imipenem-susceptible. Although it was possible to demonstrate the presence of ISPa46 in all strains by PCR, this IS was transposed in the oprD gene only for imipenem-resistant isolates. Therefore, this study reports a novel IS element (ISPa46) in P. aeruginosa clinical isolates of a CF patient in Marseille, France, that was associated with carbapenem resistance and was selected in the absence of carbapenem treatment.
authors.affiliation: Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UMR CNRS-6236, IRD198, IHU Méditerranée Infection, Aix-Marseille Université, 27 Bd Jean Moulin, 13005 Marseille, France.
authors.forename: Seydina M
authors.initials: SM
authors.lastname: Diene
authors.forename: Tiphanie
authors.initials: T
authors.lastname: L'homme
authors.forename: Sophia
authors.initials: S
authors.lastname: Bellulo
authors.forename: Nathalie
authors.initials: N
authors.lastname: Stremler
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Dubus
authors.forename: Laurent
authors.initials: L
authors.lastname: Mely
authors.forename: Sylvie
authors.initials: S
authors.lastname: Leroy
authors.forename: Nicolas
authors.initials: N
authors.lastname: Degand
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Rolain
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D003550:Cystic Fibrosis / Q000382:microbiology; D004251:DNA Transposable Elements / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005260:Female; D005602:France; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D055029:Inverted Repeat Sequences / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D018272:Porins / Q000235:genetics*; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D018272:Porins; C077157:OprD protein, Pseudomonas aeruginosa; D015378:Imipenem; D001618:beta-Lactamases; C063912:carbapenemase
keywords: Carbapenem resistance; Cystic fibrosis; Insertion sequence; OprD porin; Pseudomonas aeruginosa