Study of drug resistance and ompA gene existence in clinical Acinetobacter baumannii isolates

Abstract

Background and Aim: Acinetobacter baumannii is one of the most important multi drug-resistant species associated with nosocomial infections. Several factors involve in resistance to drug and its pathogenicity. Of these factors, OmpA protein plays a crucial role. Therefore, the aim of current research was to assess resistance to drug and also ompA gene existence in A. baumannii isolated from clinical sources. Materials and Methods: Firstly, clinical samples were collected from Imam Khomeini, Milad and Motahari Hospitals during 2015-2016 years and the final confirmation were done by using biochemical methods. Afterwards, susceptibilities to antibiotics of different classes were determined by disc diffusion method and presence of ompA gene was checked by using PCR method and verified by sequencing. Results: The results show that of 650 clinical samples, 156 (24%) of isolates were formed of A. baumannii and mostly showed resistance to different classes of antibiotics. 92.95% of isolates were multi drug resistance (MDR) and finally 86.53% were extremely drug resistance (XDR). All of them contained ompA gene. Conclusions: Existence of multi drug resistance in most isolates as well as presence of ompA in all samples can cause bacterial virulence and drug resistance. It seems essential to provide continuous monitoring and determination of antibiotic susceptibility of clinical A. baumannii, decrease the moral and material damage caused by the bacteria