β-lactamase genes in carbapenem resistance Acinetobacter baumannii isolates from a Turkish university hospital

Abstract

Introduction: The spread of Acinetobacter baumannii, resistant to most of the available antimicrobial agents, is a serious health problem. The high rate of carbapenem resistance among Acinetobacter baumannii isolates is considered as a threat to public health. In this study, we aimed to determine the antibiotic resistance and related genes in carbapenem-resistant Acinetobacter baumannii isolates.
 Methodology: Ninety six isolates of A. baumannii were included. Antimicrobial susceptibility was performed by Phoenix Automated System and disk diffusion method. Carbapenem resistane was characterized by scrneeing of resistance genes such as blaTEM, blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES, blaNDM, blaVIM, blaIMP and blaOXA23-24-51-58 using multiplex polymerase chain reaction.
 Results: Resistance for the levofloxacin, gentamicin, amikacin, and tigecycline were determined as 96.9%, 93.7%, 72.9% and 45.8% respectively. Colistin was the only susceptible antibiotic against all clinical isolates. All isolates were defined as multidrug resistance and of these, 31.2% were extensively drug-resistant (sensitive only to colistin). BlaOXA-51­ and blaOXA-23 genes were detected in 100% strains while blaTEM was found in only 2% strains. There was no amplification for the blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES blaNDM, blaVIM, blaIMP and blaOXA24-58 genes.
 Conclusions: The high frequency of blaOXA-23 and low frequency of blaTEM gene was observed that indicate prevalence of a variety of A. baumannii strains. The rates of resistance genes vary from region to region. Studies are required for the prevention and control of A. baumannii infection and to formulate the strategies of antibiotic usage.

Do Seasonal Changes and Climate Effect the Prevalence of Antibiotic Resistance of <i>Acinetobacter calcoaceticus-baumannii</i> Complex?

“…In this study, the resistance of the ABC strains to amikacin, ciprofloxacin, gentamisin, imipenem and meropenem were 78.8%, 85%, 81.9%, 85.1% and 86.6%, retrospectively. In our study, the rates of resistance to the indicated antibiotics were consistent with the literature [23][24][25].…”

Investigation of Class 1 Integrons With Antibiotic Resistance Genes in Multidrug-Resistant Acinetobacter Baumannii Strains and Determination of Plant Extract Effects on Multidrug-Resistant Isolates

“…In a multicentre study conducted in 2016 in Turkey, 443 isolates of A. baumannii were studied, and CTX-M-1 was identified in 63 isolates and CTX-M-2 in 42 isolates [18]. The presence of CTX-M-1 and CTX-M-2 β-lactamases in 96 A. baumannii isolates from Turkey was investigated and no positive results were obtained for the isolates [19]. In the same study, the presence of OXA- [20].…”

High prevalence of TEM, VIM, and OXA-2 beta-lactamases and clonal diversity among Acinetobacter baumannii isolates in Turkey

“…In this study, we found that all the isolated strains were susceptible to tigecycline and colistin. However, there have been many reports of tigecycline and colistin resistance, which range from 0.6% to 45.8% [18][19][20][21] and 0 to 30.6%, respectively, around the world [22][23][24][25]. Furthermore, colistin resistance was reported to be of 4% in the EARS-Net 2016 report [26].…”

“…Prior to the discovery of bla OXA-23, the OXA enzymes were thought to be a small group of enzymes encoded by plasmids that affected only penicillins; the migration of these genes via transposons caused them to become the dominant mechanism of antibiotic resistance [4]. The frequency of bla OXA-23 in A. baumannii strains has been reported to range from 32% to 100% in Turkey [21,31,32] and from 28% to 96% worldwide [33][34][35][36].…”

“…Similarly, Beriş et al reported that the frequency of bla TEM and bla SHV in Turkey was 55.7% and 7.7%, respectively [18]. Conversely, Coşkun et al reported a low frequency of bla TEM (2%) [21]. The frequency of bla TEM has been reported to be 2.9%-71% worldwide [19,38,39].…”