Early detection of metallo-beta-lactamase NDM-1-and OXA-23 ă carbapenemase-producing Acinetobacter baumannii in Libyan hospitals

International audienceAcinetobacter baumannii is an opportunistic pathogen causing various ă nosocomial infections. The aim of this study was to characterise the ă molecular support of carbapenem-resistant A. baumannii clinical isolates ă recovered from two Libyan hospitals. Bacterial isolates were identified ă by matrix-assisted laser desorption/ionisation time-of-flight mass ă spectrometry (MALDI-TOF/MS). Antibiotic susceptibility testing was ă performed using disk diffusion and Etest methods, and carbapenem ă resistance determinants were studied by PCR amplification and ă sequencing. Multilocus sequence typing (MLST) was performed for typing ă of the isolates. All 36 imipenem-resistant isolates tested were ă identified as A. baumannii. The bla(OXA-23) gene was detected in 29 ă strains (80.6%). The metallo-beta-lactamase bla(NDM-1) gene was ă detected in eight isolates (22.2%), showing dissemination of ă multidrug-resistant (MDR) A. baumannii in Tripoli Medical Center and ă Burn and Plastic Surgery Hospital in Libya, including one isolate that ă co-expressed the bla(OXA-23) gene. MLST revealed several sequence types ă (STs). Imipenem-resistant A. baumannii ST2 was the predominant clone ă (16/36; 44.4%). This study shows that NDM-1 and OXA-23 contribute to ă antibiotic resistance in Libyan hospitals and represents the first ă incidence of the association of these two carbapenemases in an ă autochthonous MDR A. baumannii isolated from patients in Libya, ă indicating that there is a longstanding infection control problem in ă these hospitals. (C) 2016 Elsevier B.V. and International Society of ă Chemotherapy. All rights reserved