Co-occurrence of bla(NDM-1) with bla(OXA-23) or bla(OXA-58) in clinical multidrug-resistant Acinetobacter baumannii isolates in Algeria

Abir Ramoul , Lotfi Loucif , Sofiane Bakour , Sabrina Amiri , Mazouz Dekhil , Jean-Marc Rolain (1)

1 URMITE - Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes

The aim of this study was to characterise the mechanisms of carbapenem resistance in Acinetobacter baumannii strains isolated in an Algerian hospital. A total of 43 imipenem-resistant A. baumannii clinical isolates collected between 2010 and 2013 were identified using API 20NE and were confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Antibiotic susceptibility testing was performed by the disk diffusion and Etest methods. Carbapenemase activity was detected using microbiological tests and PCR. Genetic transfer of the bla(NDM-1) gene was performed by conjugation using sodium azide-resistant Escherichia coli J53 as recipient strain. Clonal relationships were studied by multilocus sequence typing (MLST) using partial sequences of the csuE and bla(OXA-51) genes. All 43 A. baumannii isolates were resistant to imipenem with high minimum inhibitory concentrations (MICs) (> 32 mu g/mL). The strains harboured bla(OXA-23), bla(NDM-1), bla(OXA-58) and/or bla(OXA-24) genes. Co-existence of bla(NDM-1) and bla(OXA-23) or bla(OXA-58) was detected in two isolates and one isolate, respectively. NDM-1 plasmid transfer to E. coli J53 was successful only for one of the three strains harbouring both bla(NDM-1) and bla(OXA-23) or bla(OXA-58). The phylogenetic tree obtained from concatenation of the partial sequences of csuE and bla(OXA-51) showed that there was no genetic relationship between the isolates and the bla(NDM-1) resistance gene. Here we report for the first time the co-occurrence of bla(NDM-1) along with bla(OXA-23) or bla(OXA-58) in recent clinical isolates of A. baumannii from Northeast Algeria. These findings re-emphasise the dissemination and rapid spread of blaNDM-1 carbapenemase genes in multidrug-resistant clinical A. baumannii isolates in Algeria. (C) 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Domaines: Maladies infectieuses

Abir Ramoul, Lotfi Loucif, Sofiane Bakour, Sabrina Amiri, Mazouz Dekhil, et al.. Co-occurrence of bla(NDM-1) with bla(OXA-23) or bla(OXA-58) in clinical multidrug-resistant Acinetobacter baumannii isolates in Algeria. Journal of Global Antimicrobial Resistance, 2016, 6, pp.136-141. ⟨10.1016/j.jgar.2016.05.003⟩. ⟨hal-01455609⟩