Characterisation of Methicillin-Resistant Staphylococcus aureus (MRSA) from Poultry, Workers, and Environment in Poultry Farms in Ogun State

The emergence of MRSA in livestock settings raises significant One Health concerns, as poultry-associated MRSA strains can colonise farm workers and enter human clinical environments through zoonotic and food-borne pathways. This study characterises MRSA from poultry birds, farm workers, and farm environments in Ogun State, South West Nigeria. Nasal swabs from 200 birds and 60 farm workers, and surface swabs from 10 poultry farms in Abeokuta North and Ifo LGAs, were cultured on selective chromogenic MRSA media. Confirmation used cefoxitin disk testing and mecA gene PCR. MRSA isolates were typed by staphylococcal protein A (spa) typing. MRSA prevalence was 18 percent in poultry, 13 percent in farm workers, and 25 percent in environmental swabs. Spa typing identified t011 and t034, livestock-associated MRSA (LA-MRSA) types, in both poultry and farm worker isolates, confirming zoonotic transmission. Human-adapted t008 was found exclusively in farm worker isolates. Multi-locus sequence typing of selected isolates assigned them to CC398, the dominant global LA-MRSA lineage. Tetracycline and erythromycin resistance was near universal in LA-MRSA isolates. The study constitutes the first molecular characterisation of LA-MRSA in Ogun State poultry farms, highlighting an occupational and food safety risk requiring integrated surveillance of veterinary and human Staphylococcus aureus populations. Keywords: MRSA, livestock-associated, poultry, One Health, Ogun State