Multiplex PCR for Genotyping and Identifying a Novel Toxin in Bovine Salmonella

Salmonella enterica Typhimurium DT104 is a major strain of Salmonella linked with food-borne illness and a significant concern to the beef industry. DT104 strains are often multiply drug-resistant and are easily spread in the close parameters of beef cattle ranches. A toxin found on the genome of DT104 strains, called art AB, has homology to other well characterized bacterial toxins. The goal of this study is to find an efficient way of genotyping and identifying the art AB toxin in bovine Salmonella isolates. The primary method used is Multiplex Polymerase Chain Reaction (MPCR), which allows for simultaneous PCR of multiple genes. We obtained four sets of primers to identify Salmonella species, phage type and art AB. In separate trials using 8 agricultural Salmonella samples we have found that the MPCR program is effective and will work for continued genotyping. Art AB has thus far been found in 3 of 8 samples and correlates well with DT104. This work will help to define the importance of art AB in bovine disease and may lead to the development of new vaccines.