An Outbreak of Carbapenem-Resistant Acinetobacter baumannii in Patients Hospitalized in Intensive Care Units of a Hospital in Western Iran

Background & Objective:  Dissemination of multiple drug-resistant Acinetobacter baumannii in hospitals, particularly in intensive care units (ICUs), may lead to serious outcomes. We aimed to investigate clonal relatedness and the presence of carbapenemase genes in clinical A. baumannii isolated during a hospital outbreak.  Materials & Methods:  From October to December ۲۰۲۰, ۴۱ A. baumannii were isolated from patients hospitalized in the ICUs of a university hospital in Kermanshah, western Iran. The sensitivity of isolates to antimicrobial agents was evaluated. The polymerase chain reaction determined the presence of OXA carbapenemases and metallo beta-lactamases. The genetic relationships of isolates were determined using the Enterobacterial repetitive intergenic consensus (ERIC) sequences analysis followed by the Pasteur multilocus sequence typing (MLST) scheme. Results:  All ۴۱ isolates showed resistance to carbapenem meropenem. The blaVIM gene was found in all isolates. Of the ۴۱ isolates, ۸۵.۴% carried blaOXA-۲۴ and ۴۸.۸% blaOXA-۲۳. No isolate harbored blaOXA-۵۸. Twenty-three isolates (۵۶.۱%) had the ISAba۱ upstream of the blaOXA-۵۱-like gene. All isolates showed multidrug resistance. ERIC typing revealed the genetic relatedness of isolates. MLST showed that some isolates belonged to sequence type (ST) ۴۱۵. Conclusion:  The results showed a high level of resistance and clonal spread of A. baumannii in our hospital's ICUs. ST۴۱۵ might be an emerging A. baumannii lineage carrying carbapenem resistance determinants, and creating awareness regarding preventing this ST may be necessary. Characterization of antimicrobial resistance and determination of genotypes will help track the recurrent episodes of infections with the described A. baumannii isolates.

کلیدواژه ها:

Drug resistance ، beta-Lactamases ، Molecular typing ، OXA carbapenemase ، Clonal spread