Low contamination of Campylobacter spp. on chicken carcasses in Minas Gerais state, Brazil: Molecular characterization and antimicrobial resistance

Here, we evaluated Campylobacter contamination on chicken carcasses and phenotypic and genotypic profiles of antimicrobial resistance of the isolated strains. A total of 95 of samples were collected from 19 slaughterhouses from Minas Gerais - Brazil, and analyzed by MPN-PCR method. Campylobacter was found in 16.8% of samples with microbial load ranging from 60 to 184 MPN/carcass. All isolates were resistant to at least 5 (31.2%) of the antimicrobials screened using the disk diffusion method. Thr-86-Ile gyrA mutation, blaOxA-61 and tet(O) genes were found in 95%, 100% and 40% resistant isolates to ciprofloxacin, ampicillin and tetracycline, respectively. Almost all isolates (90%) showed the three genes required to synthesize the CmeABC efflux system. The use of efflux pump inhibitor (PAβN) resulted in a significant reduction in the MICs of antimicrobials (2–128 fold), indicating the importance of efflux systems in conferring antimicrobial resistance. Campylobacter were detected at low concentrations in Brazilian chicken carcasses. However, high-levels of antimicrobial resistance were observed and associated with several mechanisms. This study provides a baseline survey on contamination of Campylobacter in Brazilian chicken carcasses and its antimicrobial resistance, giving support for actions directed at reducing this pathogen in the food chain.