Frequency of class 2 integrons in multidrug-resistant Acinetobacter baumannii isolated from patients in West of Iran

Background and Objective: The acquisition and dissemination of antibiotic-resistant agents in Acinetobacter baumannii ( A. baumannii ) is highly facilitated through integrons that are DNA transposable elements and able to receive genes through site-specific recombination. Class 1 and 2 integrons are the most known integrons that are frequently available in A. baumannii . The aim of this study was to determine the frequency of class 2 integron in multidrug resistance (MDR) A. baumannii . Methods: A total of 100 isolates of A. baumannii were collected from patients that are admitted to hospitals in Kermanshah in the year 2014-2015. The isolates were identified using biochemical tests and the kit API 20 NE, and then their sensitivity to 20 antibiotics was examined. The prevalence rate of class 2 integrons among the isolates was determined using Polymerase chain reaction (PCR). The results were analyzed using Fisher's test and the non-parametric Chi-squared test. Results: The maximum drug resistance was observed against Cefotaxime (93%), Ceftriaxone (92%), Mezlocillin (91%), Ceftazidime (86%), Imipenem (82%), and Piperacillin (82%). The minimum drug resistance was observed against Colistin (12%), Polymyxin B (7%), Minocycline (10%), and Tigecycline (6%) and seems as the most efficient antibiotics. Twenty-nine (29%) isolates out of the 100 isolates were multidrug resistance (MDR); about 21 isolates (21%) were extensive drug resistance (XDR); and none were pan drug resistance (PDR). Thirty four (34%) isolates contained class 2 integrons. The results did not showed a significant correlation between the presence of class 2 integrons and incidence of MDR A. baumannii . Conclusion: The transmission of antibiotic-resistant agents by the class 2 integrons resulted in further durability and spread of these isolates in the environment. Therefore, it seems that resistance to A. baumannii is always changing, and different countries should attend to these changes.