Detection of plasmid mediated pAMC and beta- lactamase resistance genes in Acinetobacter baumannii isolates

Nosocomial infections caused by Acinetobacter (A.) baumannii are recognized as a serious threat to public health worldwide. A. baumannii causes serious infections that are difficult to treat today due to the development and increase of resistance to many beta- lactam antibiotics. In this study, beta-lactam resistant 29 A. baumannii isolates isolated from different clinical samples stored in Kırşehir Ahi Evran University Medical Microbiology Laboratory culture collection were aimed to detect plasmid mediated pAMC (blaMOX , blaCIT , blaDHA, blaACC, blaFOB) and beta-lactam resistance genes (blaTEM, blaSHV, blaCTX-M1, blaCTX-M2, blaGES, blaVEB, blaOXA-1). Conventional PCR was used to identify beta-lactam resistance genes and plasmid mediated pAMC genes. All of the isolates were resistant to imipenem, piperacillin/tazobactam and ceftazidime, while tigecycline was susceptible. Among the beta-lactamase resistance genes in A. baumannii isolates, blaTEM, blaSHV, blaCTX-m1, blaCTX-m2, blaOXA-1 and blaGES genes were determined as 9 (%31), 16 (%55.1), 2 (%6.8), 10 (%34.4), 2 (%6.8) and 20 (68.9), respectively. Among the plasmid-mediated pAMC resistance genes in isolates, blaDHA gene was determined in only one isolate. Conjugative plasmid was detected in 3 isolates examined in the study. One of these isolates, whose antibiotic susceptibility was determined by disc diffusion method, was found to be resistant to 8 different antibiotics (Ampicillin, ceftriaxone, amoxicillin- clavulanic acid, cefotaxine, piperacillin/tazobactam, ceftazidime, aztreonam and trimethopsim), while the other two were only resistant to two antibiotics (ampicillin and amoxicillin-clavulonic acid) was found to be resistant. In conclusion; In this study, it is thought that the presence of conjugative plasmid in A. baumannii isolates potentially poses serious risks in the spread of antibiotic resistance, so more comprehensive analyzes should be conducted on the subject. February, 2024, 66 pages. Keywords: Acinetobacter baumannii , β-Lactamases, pAmpC, conjugative plasmid.