Molecular Analysis of Oxacillinase Genes and Identification of Drug Resistance Pattern in MDR Strains of Acinetobacter baumannii Isolated from Burn Wound Samples in Kermanshah, Iran
Research Assistant, Department of Microbiology, Kermanshah University of Medical Sciences and Ph.D. Student of Medical Bacteriology, Pasteur Institute of Iran, Kermanshah, Iran.
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Introduction: Carbapenem Resistant Acinetobacter Baumannii (CRAB) is a dangerous nosocomial pathogen that can cause high mortality in patients. This bacterium has a remarkable ability to acquire various resistance mechanisms due to this it is considered as one of the health priorities.
Aim: To investigate the prevalence of the OXA-23, OXA-24, and OXA-58 genes in Acinetobacter baumannii isolates collected from burn wound samples in Kermanshah, Iran.
Materials and Methods: A cross-sectional study was done during 11 months period from December 2018 to October 2019, 74 A. baumannii isolates were collected from those admitted to the Burns Unit of Imam Khomeini Hospital in Kermanshah, Iran. The 74 A. baumannii isolates were detected using particular bacteriological methods. Following determination of the antibiotic sensitivity of the specimens using the disk diffusion technique, polymerase chain reaction was performed to determine the frequency of the OXA-23, OXA-24, and OXA-58 genes using their specific primers. Data were analysed using Fisher’s-exact test and Chi-squared test in Statistical Package for the Social Sciences (SPSS) version 20.0. A p-value <0.05 was considered statistically significant.
Results: All the 74 A. baumannii isolates were Multidrug-Resistant (MDR) (41 from males and 33 from females). The highest drug resistance was against cefotaxime (100%) and piperacillin (98.6%), while all the isolates were sensitive to polymyxin B and colistin. Oxacillinase genes with the highest and lowest frequencies were OXA-23 (64.7%) and OXA-58 (3.5%), respectively. The highest frequency of isolates with two genes were related to OXA-23 and OXA-24. A significant relationship was observed among the existence of oxacillinase genes and resistance to some antibiotics.
Conclusion: The results of this study indicated the significance of OXA carbapenemase genes in burn patients. Due to the high drug resistance of A. baumannii isolates collected from wound samples, the identification of carbapenemase-producing A. baumannii isolates is paramount in developing prevention and control programs for these drug-resistant isolates.