Investigation of marA Efflux Pump Gene Expression in Ciprofloxacin Resistant Salmonella enteritidis Clinical Strains Using Real-Time PCR

Ciprofloxacin-resistant Salmonella spp. are among the most important causative agents of food-borne infections. The marA efflux pump in this bacterium plays a significant role in the development of drug resistance. The aim of this study was to investigate marA efflux pump gene expression in Ciprofloxacin resistant Salmonella enteritidis clinical strains by Real Time PCR.

In this cross-sectional study, strains of Salmonella enteritidis were isolated from clinical specimens of feces using microbial methods. Antibiotic resistance of ciprofloxacin-resistant strains was evaluated by disk diffusion method. The presence of marA efflux pump in the clinical strain of Salmonella enteritidis, intermediate ciprofloxacin-resistant, was evaluated using Cart-wheel and PCR. The results of this study were analyzed using SPSS 21 software and one-way ANOVA.

From the 1200 fecal clinical specimens, 60 Salmonella enteritidis were isolated. The highest resistance was related to 9 strains (15%) and 11 intermediate strains (18%) ciprofloxacin. and the least resistance was related to imipenem and chloramphenicol (100% sensitive). The results of cartwheel and PCR methods showed that all strains intermediate or resistant to ciprofloxacin had a marA efflux pump. Finally, Real-Time PCR results showed a significant up-regulation of marA gene in S. enteritidis strains.

According to the results of Real-Time PCR, it seems that the marA efflux pump gene is one of the resistance agents in ciprofloxacin-resistant Salmonella enteritidis.