Prevalence of Extended-Spectrum β-Lactamases and Antibiotic Resistance Patterns in Acinetobacter baumannii Isolated from Clinical Samples in Kermanshah, Iran

Background: Acinetobacter is an opportunistic bacterial pathogen with intrinsic and acquired resistance to many antibiotics. Objectives: This study aimed to determine the prevalence of extended-spectrum beta-lactamases (ESBLs) and antibiotic resistance patterns in A. baumannii isolated from clinical samples at Imam Reza hospital in Kermanshah, Iran, using phenotypic and genotypic methods. Methods: In this descriptive-analytical study, 80 Acinetobacter isolates obtained from clinical samples were confirmed using standard biochemical tests. After antibiotic susceptibility testing using disk diffusion method, the presence of ESBLs was detected using the combined disk test (CDT). The Polymerase chain reaction (PCR) method was employed to identify the frequency of blaTEM, blaCTX-M, and blaSHV genes using their specific primers. Results: Among the A. baumannii isolates, 62.5% showed multidrug resistance (MDR). The highest rate of antibiotic resistance was to ceftriaxone (100%), followed by amikacin (96.2%), and the lowest was to polymyxin B (13.8%) and ampicillin/sulbactam (52.8%). Forty-three (53.8%) ESBL-producing isolates expressing SHV (n = 18, 41.9%), TEM (n = 11, 25.6%), and CTX-M (n = 3, 7%) genes were identified. Conclusions: This study revealed an increased prevalence of ESBL-encoding genes in A. baumannii isolates. The increased frequency of these genes may be due to overuse or inappropriate use of antibiotics in this region. To combat overuse and prevent further development of drug resistance in Kermanshah, Iran, more attention should be paid to prescribing practices for various antibiotics, including cephalosporins.