2013 Annual Report
2. Determine the efficacy and efficiency of this hybridization protocol in detecting the presence, quantity, and relative distribution of the targeted S. enterica serotypes under different cultural and environmental conditions.
3. Expand the utility of the hybridization protocol to include one, or a combination of the following: (1) Additional SNPs within the cyaA gene; (2) SNPs within other target genes such as SEN4316, SEN3898, SEN4256, and SEN1164; (3) Detection of serotypes on environmental samples across the “food to fork” continuum within the poultry industry.
Development of S. enterica serotyping/pathotyping SNP detection assay. ARS scientists in Athens, GA developed a serotyping/Pathotyping assay based on single base pair genetic differences (known as SNPs) within the adeylate cyclase (cyaA) gene and optimized for use with the Luminex MagPlex® system. The assay successfully differentiated between three S. Enteritidis serotypes, as well as S. Typhimurium and S. Kentucky, and was able to successfully type strains within pure cultures and in mixed cultures containing up to the 5 reference strains in varying concentrations). Environmental Salmonella isolates (recovered from various sections of the production/processing chain) were also used to successfully validate the efficacy of this novel assay. Results of this study will provide a new serotyping/pathotying tool to researchers and commercial producers/processors to rapidly identify Salmonella strains isolated from throughout the poultry production spectrum.
Development of a second-generation SNP assay to further delineate between Salmonella enterica serotypes relevant to poultry food safety. ARS scientists in Athens GA are developing a secondary SNP-based assay to further differentiate important food-safety related Salmonella found within the poultry production/processing chain. The SNP assay previously developed by these scientists (based on the cyaA gene) was unable to distinguish between the two of the major Salmonella zoonoses in poultry processing (Typhimurium and Heidelberg), therefore a new SNP assay was developed based on the UDP sugar hydrolase (ushA) gene that distinguishes between Heidelberg and Typhimurium (as well as the Enteritidis, Kentucky and Infantis serotypes). Results of this study, when combined with the previous SNP assay developed for this project, will provide researchers and the poultry industry with a powerful new tool to rapidly identify major zoonotic Salmonella strains isolated from within the poultry production/processing environment.