title: Antimicrobial-Resistant Campylobacter in Organically and Conventionally Raised Layer Chickens.
abstract: Poultry is a major source of Campylobacter, which can cause foodborne bacterial gastroenteritis in humans. Additionally, poultry-associated Campylobacter can develop resistance to important antimicrobials, which increases the risk to public health. While broiler chickens have been the focus of many studies, the emergence of antimicrobial-resistant Campylobacter on layer farms has not received equal attention. However, the growing popularity of cage-free and organic layer farming necessitates a closer assessment of (1) the impact of these farming practices on the emergence of antimicrobial-resistant Campylobacter and (2) layers as a potential source for the transmission of these pathogens. Here, we showed that the prevalence of Campylobacter on organic and conventional layer farms was statistically similar (p > 0.05). However, the average number of Campylobacter jejuni-positive organically grown hens was lower (p < 0.05) in comparison to conventionally grown hens. Campylobacter isolated from both production systems carried antimicrobial resistance genes. The tet(O) and cmeB were the most frequently detected genes, while the occurrence of aph-3-1 and blaOXA-61 was significantly lower (p < 0.05). Farming practices appeared to have an effect on the antimicrobial resistance phenotype, because the isolates from organically grown hens on two farms (OF-2 and OF-3) exhibited significantly lower resistance (p < 0.05) to ciprofloxacin, erythromycin, and tylosin. However, on one of the sampled organic farms (OF-1), a relatively high number of antimicrobial-resistant Campylobacter were isolated. We conclude that organic farming can potentially impact the emergence of antimicrobial-resistant Campylobacter. Nevertheless, this impact should be regularly monitored to avoid potential relapses.
authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University , Wooster, Ohio.
authors: Issmat I
authors: II
authors: Kassem
authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University , Wooster, Ohio.
authors: Olugbenga
authors: O
authors: Kehinde
authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University , Wooster, Ohio.
authors: Anand
authors: A
authors: Kumar
authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University , Wooster, Ohio.
authors: Gireesh
authors: G
authors: Rajashekara
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002167:Campylobacter / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D002645:Chickens / Q000382:microbiology*; D002939:Ciprofloxacin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004917:Erythromycin / Q000494:pharmacology; D005243:Feces / Q000382:microbiology; D005506:Food Contamination; D005516:Food Microbiology; D005798:Genes, Bacterial; D008826:Microbial Sensitivity Tests; D011200:Poultry; D014422:Turkeys / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D004917:Erythromycin
keywords: C. coli; C. jejuni; Campylobacter; antimicrobial resistance; food safety; layer chickens; organic farms