Characterization of Antimicrobial Resistance in Species from Broiler Chicken Litter.

Campylobacteriosis in human populations is an ongoing issue in both developed and developing countries. Poultry production is recognized as a reservoir for antimicrobial resistance and main source of human infection. : In this study, sixty-five isolates were cultured from fecal samples collected from 17 flocks of broiler chickens in Alberta, Canada over two years (2015-2016). Susceptibility assays and PCR assays were performed to characterize resistance phenotypes and resistance genes. Conjugation assays were used to examine the mobility of AMR phenotypes. : was the predominant species recovered during both years of sampling. There were no isolates found in 2015; however, approximately 33% (8/24) of isolates collected in 2016 were . The two most frequent antimicrobial resistance patterns in collected in 2015 were tetracycline (39%) and azithromycin/clindamycin/erythromycin/telithromycin resistance (29%). One isolate collected in 2015 has resistance pattern ciprofloxacin/nalidixic acid/tetracycline. The gene was detected in all tetracycline resistant isolates from 2015. The gene was detected in all species isolates with resistance to azithromycin/clindamycin/erythromycin/telithromycin, and from two isolates with tetracycline resistance. Alignment of the nucleotide sequences of the gene from isolates with different resistance patterns revealed several single nucleotide polymorphisms. A variety of multi-drug resistance patterns were observed through conjugation experiments. : These data suggest that poultry production may serve as a potential reservoir for and source of transmission of multi-drug resistant and supports the need for continued surveillance.