Pierre Bogaerts1, Thierry Naas2,3,4, Veroniek Saegeman5, Remy A Bonnin3,4, Annette Schuermans5, Stéphanie Evrard1, Warda Bouchahrouf1, Thomas Jove6, Didier Tande7, Xavier de Bolle8, Te-Din Huang1, Laurent Dortet2,3,4, Youri Glupczynski1. 1. Laboratory of Clinical Microbiology, Belgian National Reference Center for Monitoring Antimicrobial Resistance in Gram-negative Bacteria, CHU UCL Namur, Yvoir, Belgium. 2. Bacteriology-Hygiene unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France. 3. EA7361 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Université Paris Sud, Université Paris Saclay, LabEx Lermit, Faculty of Medicine, Le Kremlin-Bicêtre, France. 4. Associated French National Reference Center for Antibiotic Resistance: Carbapenemase-producing Enterobacteriaceae, Le Kremlin-Bicêtre, France. 5. Laboratory of Microbiology, UZ Leuven, Leuven, Belgium. 6. UMR Inserm 1092, Université de Limoges, Limoges, France. 7. Laboratoire de Microbiologie, CHRU Brest, Brest, France. 8. Unité de Recherche en biologie des micro-organismes, Université de Namur, Namur, Belgium.
Abstract
Objectives: To describe a novel plasmid-borne class D carbapenemase (CHDL) named OXA-427 identified in several Enterobacteriaceae clinical isolates from nine patients in one Belgian hospital. Methods: OXA-427-producing isolates were analysed by an electrochemical imipenem hydrolysis method (BYG Carba test), Carba NP test, conventional phenotypic assays and by molecular methods (PCR, whole sequencing of the OXA-427-encoding plasmid and cloning). The antimicrobial resistance profile of OXA-427 was analysed by expression of the cloned gene in Escherichia coli DH10B and J53. Results: Eleven OXA-427-producing Enterobacteriaceae isolates of various species were identified from clinical specimens of nine patients between March 2012 and June 2014. OXA-427 shares only 22%-29% amino acid identity with OXA-48-like enzymes and other acquired CHDL (e.g. OXA-23, -24/40 and -58 of Acinetobacter spp.). Conversely, it appeared closely related to the chromosomal class D β-lactamase of Aeromonas media, Aeromonas hydrophila and Aeromonas sobria (99%, 89% and 77% of identity, respectively). When expressed in E. coli, OXA-427 hydrolysed imipenem and conferred resistance to extended-spectrum cephalosporins (mostly ceftazidime), penicillins including temocillin, and reduced susceptibility to carbapenems. The blaOXA-427 gene was located in a 45 kb resistance island on a 177 kb IncA/C plasmid. Conclusions: OXA-427 is a novel CHDL most closely related to chromosomal class D β-lactamase of A. media WS. It confers resistance to penicillins, ceftazidime and aztreonam and in some instances to carbapenems. OXA-427, which is not detectable by classical molecular tests, caused a protracted outbreak in one university hospital over a 2 year period.
Objectives: To describe a novel plasmid-borne class D carbapenemase (CHDL) named OXA-427 identified in several Enterobacteriaceae clinical isolates from nine patients in one Belgian hospital. Methods: OXA-427-producing isolates were analysed by an electrochemical imipenem hydrolysis method (BYG Carba test), Carba NP test, conventional phenotypic assays and by molecular methods (PCR, whole sequencing of the OXA-427-encoding plasmid and cloning). The antimicrobial resistance profile of OXA-427 was analysed by expression of the cloned gene in Escherichia coli DH10B and J53. Results: Eleven OXA-427-producing Enterobacteriaceae isolates of various species were identified from clinical specimens of nine patients between March 2012 and June 2014. OXA-427 shares only 22%-29% amino acid identity with OXA-48-like enzymes and other acquired CHDL (e.g. OXA-23, -24/40 and -58 of Acinetobacter spp.). Conversely, it appeared closely related to the chromosomal class D β-lactamase of Aeromonas media, Aeromonas hydrophila and Aeromonas sobria (99%, 89% and 77% of identity, respectively). When expressed in E. coli, OXA-427 hydrolysed imipenem and conferred resistance to extended-spectrum cephalosporins (mostly ceftazidime), penicillins including temocillin, and reduced susceptibility to carbapenems. The blaOXA-427 gene was located in a 45 kb resistance island on a 177 kb IncA/C plasmid. Conclusions: OXA-427 is a novel CHDL most closely related to chromosomal class D β-lactamase of A. media WS. It confers resistance to penicillins, ceftazidime and aztreonam and in some instances to carbapenems. OXA-427, which is not detectable by classical molecular tests, caused a protracted outbreak in one university hospital over a 2 year period.
Authors: Stefanie Desmet; Suruchi Nepal; Jan Maarten van Dijl; Marc Van Ranst; Monika A Chlebowicz; John W Rossen; Jeroen K J Van Houdt; Piet Maes; Katrien Lagrou; Erik Bathoorn Journal: Antimicrob Agents Chemother Date: 2018-02-23 Impact factor: 5.191