The Diversity of Class B and Class D Carbapenemases in Clinical Acinetobacter Baumannii Isolates Pubmed



Gholami M¹ ; Moshiri M² ; Ahanjan M¹ ; Chirani AS³ ; Bibalan MH⁴ ; Asadi A⁵ ; Eshaghi M⁵ ; Pournajaf A⁶ ; Abbasian S⁵ ; Kouhsari E⁵ ; Irajian G⁵ Show Affiliations
Source: Infezioni in Medicina Published:2018

Abstract

Wide distribution of multidrug-resistant Acinetobacter baumannii strains has become a foremost concern in hospital environments. Treatment of infections caused by multidrug resistant strains has conventionally involved the use of ß-lactams such as carbapenems. In this study, we report the distribution of carbapenemase genes in A. baumannii isolated from hospitalized patients. The study was conducted on 110 non-repetitive A. baumannii isolates collected from hospitalized patients, over a nine-month period. Clinical isolates were examined by conventional susceptibility testing, using the disk-diffu-sion method and multiplex polymerase chain reaction to detect acquired carbapenemase genes. All of the isolates were completely resistant to TOB, SXT, IPM, MEM, CTX, CRO, FEP, CAZ, CIP, PTZ, PIP and were susceptible to colistin, but moderately susceptible TET (2.72%), AK (4.54%) and GEN (3.63%). The prevalence of blaOXA-51-like, blaOXA-23-like, blaOXA-24-like, blaOXA-58-like, blaSIM and blaSPM genes was 100%, 96.36%, 35.45%, 7.27%, 7.27% and 3.63%, respectively. blaGIM and blaVIM genes were not detected among the strains. Our results suggest that OXA-type carbapenemase genes plus class B β-lactamases contribute to carbapenem resistance in the collected isolates. Therefore, quick identification of these resistant genes using molecular approaches is critical in limiting the spread of infections caused by A. baumannii. Drug administration correction of the physicians, based on antibiotic susceptibility testing and more knowledge on the nosocomial infection control policies as essential need. © 2018, EDIMES Edizioni Medico Scientifiche. All rights reserved.