Frequency of MDR Acinetobacter baumannii and the Most Common OXA- type Genes in Multiple Drug-Resistant Strains Isolated from Patients in Tabriz Imam Reza Hospital

 Background and purpose: Acinetobacter is a pathogen that could cause nosocomial infections. The present study aimed at determining Acinetobacter cases in clinical cultures of patients hospitalized in Tabriz Imam Reza Hospital to determine the frequency of the most common oxa genes causing drug resistance in these specimens. Materials and methods: In this descriptive cross-sectional study, clinical specimens including the blood, urine, tracheal secretions, ulcers, and throat specimens were collected from July to October 2017. The bacteria were isolated and identified using standard bacteriological methods. The Clinical and Laboratory Standards Institute (CLSI, 2016) guideline was used to determine bacterial susceptibility and resistance. Bacterial DNA extraction was done and the OXA genes (23, 24, 48, 58) were identified using specific primers and PCR method. Results: We identified 66 (72.52) multiple drug-resistant (MDR) Acinetobacter strains. These isolates showed 100% resistance to cefepime, cefotaxime, piperacillin-tazobactam, and meropenem. In 100% of the samples, sensitivity to colistin was observed. According to findings, there was a significant relationship between the presence of oxa24 gene and resistance to tobramycin and amikacin (P= 0.005). Conclusion: This study showed high rate of MDR Acinetobacter strains, so, nosocomial infection control is highly necessary. Strategies such as identifying infected patients, detecting bacterial colonization, sterilizing equipment and units, and controlling antibiotic use in the hospital are recommended to prevent the development of multidrug-resistant bacteria and to control nosocomial infections.