Antimicrobial resistance in nontyphoidal Salmonella.

Salmonella is one of the leading causes of foodborne illness in countries around the world. Treatment of Salmonella infections, in both animals and humans has become more difficult with the emergence of multidrug-resistant (MDR) Salmonella strains. Foodborne infections and outbreaks with MDR Salmonella are also increasingly reported. To better monitor and control the spread of MDR Salmonella, it is important to understand the mechanisms responsible for drug resistance and how drug resistance is transmitted to and between Salmonella strains. This review summarizes current knowledge on antimicrobial drugs used to treat Salmonella infections and provides an overview of MDR Salmonella in the United States and a discussion of the genetics of Salmonella drug resistance, including the mechanisms responsible for the transmission of drug-resistance genes in Salmonella, using data from the United States and other countries.