Antimicrobial Resistance, Virulence Properties and Genetic Diversity of Typhimurium Recovered from Domestic and Imported Seafood.

The quantity of seafood imported and produced by domestic aquaculture farming has increased. Recently, it has been reported that multidrug-resistant (MDR) Typhimurium may be associated with seafood. However, information is limited to the antimicrobial resistance, virulence properties, and genetic diversity of recovered from imported and domestic seafood. This study investigated the antimicrobial resistance, virulence properties, and genetic diversity of isolated from domestic and imported catfish, shrimp, and tilapia. A total of 127 isolates were tested for the presence of multidrug-resistance (MDR), virulence genes (A, C, C, R), and genetic diversity using the Sensititre micro-broth dilution method, PCR, and pulsed-field gel electrophoresis (PFGE), respectively. All isolates were uniformly susceptible to six (amoxicillin/clavulanic acid, ceftiofur, ceftriaxone, imipenem, nitrofurantoin, and trimethoprim/sulfamethoxazole) of the 17 tested antimicrobials and genetically diverse. Fifty-three percent of the isolates were resistant to at least one antimicrobial and 49% were multidrug resistant. Ninety-five percent of the isolates possessed the A gene, 67% C, and 43% for both C, and R. The results suggest that recovered from seafood is frequently MDR, virulent, and have the ability to cause salmonellosis.