Background: Recently, the rate of antibiotic resistance of Campylobacter has been reported to be increasing and the mechanism of this resistance has been reported to be related to the activity of efflux pumps. The purpose of this study was to isolate Campylobacter strains from domestic animals such as poultry and cows and evaluate the role of efflux pumps in antibiotic resistance property of them.
Methods: A total of 300 fecal samples were collected from poultry and cows and subjected to isolation of Campylobacter by preT-KB method. The isolates were identified and confirmed by phenotypic and genotypic methods and their antibiotic susceptibility was evaluated using the disk diffusion method. Efflux pump activity in the isolates was assessed by EtBr-agar cartwheel method and the presence of efflux pump cmeABC was evaluated in all isolates. Finally, the correlation between efflux pump activity and antibiotic resistance was evaluated in the isolates using inhibition of efflux pump activity of Phe-Arg β-naphthylamide.
Results: Of all samples, 10 (3.3%) Campylobacter strains were isolated. Seven (70%) and three (30%) strains were isolated from poultry and cows, respectively. Of all isolates, 9 belonged to Campylobacter jejuni and 1 belonged to Campylobacter coli. The isolates were resistant to three antibiotics, namely Ciprofloxacin, Ceftriaxone, and Cefotaxime. Efflux pump activity was observed in all isolates; however, cmeABC genes were not present in all of them. In addition, resistance to Erythromycin and Ciprofloxacin was associated with efflux pump activity.
Conclusions: All Campylobacter isolates in the current study showed antibiotic resistance and the activity of efflux pumps could induce antibiotic resistance and decrease the antibacterial activity of many drug families in Campylobacter. In addition, the activity of efflux pumps can be considered a mechanism of antibiotic resistance and elimination of this activity might increase the effectiveness of antibiotics.