1207. Acquisition and Quantification of Antimicrobial Resistance Genes in the Gut Microbiome of Ugandan Women Exposed to Small-Scale Chicken Farming

Abstract

BackgroundAntibiotic use in livestock farming is thought to be a major contributor to the spread of antimicrobial resistance (AMR) genes in humans. However, quantitative data in this in this field are rare. To address this gap in the literature, we examined the prevalence of clinically important AMR genes before and after the introduction of chicken farming among women in rural Uganda.MethodsWe recruited a subset of women participating in a waitlist-randomized controlled trial of small-scale hybrid chicken farming in rural Uganda. Tetracycline is routinely administered to chicks during brooding. Stool samples before and one year after chicken introduction were obtained from six women randomized to the control arm, from five women randomized to the intervention arm, and from chickens. Microbial DNA was extracted from chicken and human stool and screened for 87 AMR genes using validated qPCR arrays (Qiagen).ResultsThe median age was 35 years. At baseline, 10 of the women reported animal contact, most commonly goats (n = 8), free ranging village chickens (n = 7), cats (n = 4), and dogs (n = 4). During baseline testing of the women’s stool, we detected 18 genes conferring AMR to aminoglycosides, fluoroquinolones, macrolides, lincosamides, streptogramin B, Class A-C β-lactamases and tetracycline efflux pumps. Chickens harbored 23 AMR genes from the same classes as found in humans, and were also found to have vancomycin resistance genes (Van B and C) and Group D β-lactamases (OXA-58 and OXA-10). At one year, six new AMR genes emerged in controls, including one present in chickens; CTX-M-1, a Class A β-lactamase. In contrast, seven new AMR genes emerged in the intervention group, including four present in chickens: SHV, SHV(238G240E), (Class A β lactamases) and QnrS, QnrB-5 (fluoroquinolone resistance genes). Two AMR genes gained by both control and intervention groups were not present in chickens.ConclusionWomen exposed to small-scale chicken farming acquired more AMR genes compared with unexposed participants. Chickens harbored many of the genes that emerged in humans. Introduction of antibiotic-treated animals may result in the transfer of AMR genes from animals to humans, even among humans exposed to a wide range of animals at baseline.Disclosures All authors: No reported disclosures.