Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 5/21/2007
Publication Date: 5/25/2007
Citation: Uthe, J.J., Bearson, S.M., Wang, Y., Qu, L., Dekkers, J., Nettleton, D., Tuggle, C. 2007. A single nucleotide polymorphism in the porcine CCT7 gene correlates with Salmonella shedding in swine [abstract]. American Society for Microbiology. Paper No. 156. Interpretive Summary:
Technical Abstract: Salmonella shed from colonized swine can contaminate: slaughter plants and pork products during meat processing, consumable crops when swine feces is used as fertilizer, water supplies if fecal material used as crop fertilizer runs off into streams and waterways, and neighboring pigs resulting in a continuous food safety problem and animal health issue. Therefore, pre-harvest control of Salmonella in swine is an essential step in preventing foodborne disease with Salmonella. Investigations of the host-pathogen interaction through transcriptional profiling of Salmonella-infected swine have revealed a number of host genes that are differentially regulated during infection. The gene encoding CCT7, a molecular chaperone involved in tubulin folding and protection, was transcriptionally induced approximately 2-fold at 2, 7 and 21 days following experimental inoculation of pigs with either Salmonella enterica serovar Typhimurium or Choleraesuis compared to the non-infected pigs. Using Sequencher analysis and the TIGR website http://compbio.dfci.harvard.edu/tgi/cgi-bin/tgi/gimain.pl?gudb=pig, a potential single nucleotide polymorphism (SNP) was identified in the sequence of CCT7 at nucleotide 1026 relative to start codon. A DNA restriction enzyme assay was developed to determine if a correlation exists between the identified SNP and fecal shedding of Salmonella in swine. Correlation analysis revealed a positive association (p<0.05) of SNP genotype A/G of the CCT7 gene with Salmonella shedding at 7 days post-inoculation (dpi)of 40 pigs experimentally inoculated with serovar Typhimurium compared to the G/G heterozygote genotype. Furthermore, a positive correlation was also observed between the SNP in CCT7 and circulating neutrophils and WBCs at 7 dpi (p<0.05), with a greater number of blood neutrophils and WBCs in the pigs with the A/G genotype compared to G/G. Identifying genetic polymorphisms in porcine genes that respond to Salmonella infection may identify swine genetic targets for improved resistance to Salmonella through industry breeding programs, thereby improving food safety.