1. Determine the prevalence of generalized transducing phages among multi drugresistant Salmonella of bovine-origin.<P>
2. Determine the susceptibility of bovine-origin Salmonella to transducing phages
isolated from multi drug-resistant Salmonella.
3. Determine the frequency of antibiotic resistance gene transduction among different
serovars of bovine-origin Salmonella.
Findings: Wild-type phage is common among Salmonella of bovine origin. Many phages have broad host ranges and are able to multiply in various serovars of Salmonella, which may facilitate the genetic exchange among Salmonella in the environment. β-lactam resistance and tetracycline resistance can be transduced from S. Heidelberg to S. Typhimurium via wild-type phage transduction. Phage-mediated antibiotic resistance transfer may contribute to the emergence and dissemination of antibiotic-resistant Salmonella in the food production environment.