Environmental Burden of Antibiotic Resistance Genes in Water Bodies Near Livestock Farms in Ogun State

Agricultural discharge from livestock farms is increasingly recognized as a significant source of antibiotic resistance genes in environmental water bodies, posing One Health implications. This study quantified the environmental burden of antibiotic resistance genes in surface water near livestock farms in Ogun State, South West Nigeria. Water samples were collected from 30 sampling points across rivers and streams adjacent to poultry, pig, and cattle farms in Abeokuta and Sagamu Local Government Areas. DNA was extracted from filtered water and analyzed by quantitative polymerase chain reaction targeting genes encoding resistance to tetracyclines, sulfonamides, aminoglycosides, and beta-lactams. Physicochemical and microbiological parameters of water were also assessed. All target resistance genes were detected at all sampling points near livestock farms. Tetracycline resistance genes were the most abundant, with concentrations significantly higher downstream of poultry farms compared to upstream controls. Integron class 1 genes, markers of horizontal gene transfer potential, were detected in 80% of samples. Antibiotic resistance gene abundance correlated significantly with fecal coliform counts. The study concludes that livestock farm effluents in Ogun State contribute measurable quantities of antibiotic resistance genes to environmental waters. Buffer zone regulations, effluent treatment requirements for livestock farms, reduced prophylactic antibiotic use, and environmental monitoring programs are recommended. Keywords: antibiotic resistance genes, environmental contamination, livestock farms, Ogun State, One Health