Genetic relationship of VEB-3 -producing Aeromonas hydrophila isolates between fish and the river in an aquatic environment

The spread of antimicrobial-resistant bacteria in natural environments is a global concern. In the present study, we investigated the distribution of cefotaxime-resistant Aeromonas hydrophila in the gills and intestines of freshwater fish. Bacteria carrying the ampH, blaVEB-3, and cphA1 genes were more frequently isolated from the gills, and most were assigned to ST1068. A genetically related strain was identified not only in fish but also in the river water. These results suggest that fish may be a valuable tool for monitoring environmental contamination caused by antimicrobial-resistant bacteria.