Antimicrobial Resistant Bacteria Monitoring in Raw Seafood Retailed: a Pilot Study Focused on and .

In aquaculture, bacterial infections in sea animals are treated using antimicrobials. As seafood is frequently consumed in its raw form, seafood contaminated with water-borne antimicrobial-resistant bacteria presents a potential transmission route to humans and can influence food safety. In this study, we aimed to determine the abundance of water-borne bacteria in retail raw seafood and to characterize their antimicrobial resistance profiles. In total, 85 retail raw seafood samples (32 fish, 26 shellfish, 25 mollusks, and two crustaceans) were purchased from supermarkets in Japan, and water-borne bacteria were isolated. The isolated bacterial species predominantly included spp. (54.1%) and spp. (34.1%). or spp. were isolated from more than 70% of the seafood samples. Tetracycline-, sulfamethoxazole-, and/or trimethoprim/sulfamethoxazole-resistant or spp. isolates were detected in seven (21.9%) fish samples (two wild-caught and five farm-raised) harboring , , and/or genes. Sulfamethoxazole- and trimethoprim/sulfamethoxazole-resistant isolates were only detected in farm-raised fish. Tetracycline and sulfamethoxazole are commonly used in aquaculture. These results suggest that water-borne bacteria like and spp. should be the primary focus of antimicrobial-resistant bacteria monitoring to effectively elucidate their spread of bacteria via seafood.