Molecular identification and investigation of antimicrobial resistance of Campylobacter spp. isolated from chicken carcasses

Campylobacter belongs to Campylobacteraceae family and is one of the most important intestinal pathogenic bacteria. The aim of the present study was to isolate and characterize the Campylobacter spp. of poultry origin in order to assess the rate of antimicrobial resistance and to investigate the presence of integron genes.
In this study, 70 rectal swab samples from chicken carcasses were collected from a slaughterhouse in Tehran. After enrichment, 39 Campylobacter spp. were isolated, which were identified by convention biochemical tests and confirmed by a genus (cadF) and species (asp, hipO) specific polymerase chain reaction (PCR), and the primers int1 and hep2 were used to identify the class1 and class2 integrons, respectively. Moreover, antibiogram was performed by disc diffusion method, and the resistance pattern of isolates was interpreted according to the CLSI guidelines.
The results showed that all of the isolates were C. coli (100%), and the integron genes were negative among all of the isolates. Among 10 antibiotics were used, the maximum resistance was seen to Co-trimoxazole (97.36%) and Nalidixic acid (94.8%), Ciprofloxacin (87.7%), Streptomycin (89.72%), and Tetracycline (97.4%). No resistance was seen to Gentamicin.
The results indicated that strains under study showed high resistance to antimicrobial agents. Regarding the absence of integrons, it can be concluded that they do not play an important role in the resistance to these Campylobacter isolates. However, it can be proposed that other resistance mechanisms are involved in the emergence of multi-drug resistance (MDR) phenotype in this genus.