Antimicrobial Resistance, Virulence Properties and Genetic Diversity of Salmonella 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) Salmonella Typhimurium may be associated with seafood. However, information is limited to the antimicrobial resistance, virulence properties, and genetic diversity of S. Typhimurium recovered from imported and domestic seafood. This study investigated the antimicrobial resistance, virulence properties, and genetic diversity of S. Typhimurium 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 (invA, pagC, spvC, spvR), 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 Salmonella isolates were resistant to at least one antimicrobial and 49% were multidrug resistant. Ninety-five percent of the isolates possessed the invA gene, 67% pagC, and 43% for both spvC, and spvR. The results suggest that S. Typhimurium recovered from seafood is frequently MDR, virulent, and have the ability to cause salmonellosis.

The outbreaks and prevalence of antimicrobial resistant Salmonella in poultry in the United States: An overview.

Salmonella is a Gram-negative, rod-shaped, facultative anaerobic, and non-spore-forming bacterium that belongs to the family of Enterobacteriaceae and is the causative agent for typhoid/paratyphoid fever and salmonellosis. Salmonella causes the highest amount of foodborne illness among bacteria at 15.5 cases per 100,000 and causes an estimated 410,000 antibiotic-resistant infections each year in the U.S. The use of antibiotics has been a staple in poultry production for the prevention of diseases and growth promotion for the last 70 years. Due to the over-and misusage of antibiotics, there has been an emerging public health crisis. Salmonella is developing resistance and may render antibiotics inoperative in a foodborne outbreak. Poultry, when not handled properly, is a major carrier and transmitter of Salmonella, causing human illness and fatality. This review summarizes the major Salmonella outbreaks over the past three decades, the prevalence of Antimicrobial Resistant (AMR) Salmonella related to poultry, and the control measures being implemented to reduce and prevent AMR Salmonella in poultry.