Prevalence and genetic characteristics of fosB-positive Staphylococcus aureus in duck farms in Guangdong, China in 2020.

This article investigates the epidemiology of fosB-positive Staphylococcus aureus, a fosfomycin-resistant and methicillin-resistant pathogen, in waterfowl farms in Guangdong Province, China. The study found a high fosfomycin resistance rate (52.4%) among 63 S. aureus isolates from duck and goose farms, with 30.1% carrying the fosB gene located on small plasmids containing the broad host-range replication protein family 13. Molecular analyses revealed that all fosB-positive strains were multidrug-resistant MRSA, predominantly of sequence types ST9-t899 and ST164-t899, and demonstrated clonal transmission between ducks, the farm environment, and humans. The findings suggest that duck farms may serve as important reservoirs for fosB-positive S. aureus, highlighting the need for ongoing surveillance of antimicrobial resistance in waterfowl farming to assess potential public health risks.