Antimicrobial Resistance in Salmonella Bacteria
Some serotypes of Salmonella have become resistant to antimicrobial drugs, and are antibiotic-resistant.
The selection of effective antibiotics is critical for the treatment of invasive Salmonella infections, but has become more difficult as antibiotic resistance has increased.  Antibiotic-resistant Salmonella have been isolated from various food products, and have been the causative agent in several foodborne disease outbreaks in the United States. 
Trace-back investigations in outbreak settings have shown animals to be the ultimate source of infection. Antibiotic use in the animal industry is thought to contribute greatly to the prevalence of multidrug-resistant infections in humans.