1)Identify molecular mechanisms in Salmonella that impact virulence and antimicrobial resistance in the gastrointestinal environment of cattle and swine.
2)Characterize the genetic pathways in swine that respond to Salmonella infection, their relationship to carrier status, and the ability to predict and control Salmonella prevalence and ultimately food safety.
3)Investigate interactions between Salmonella and host microbiota that influence Salmonella colonization and persistence, alter the commensal composition in the host, and provide novel intervention strategies to decrease Salmonella in swine populations.
1) Use phenotypic assays, recombineering, and global transcriptional analysis to identify the genes and genetic pathways involved in regulating Salmonella DT104 hyper-invasion in response to a) rumen protozoa and b) sub-inhibitory concentrations of antibiotics.
2) Use an attenuated, LPS/flagella-deficient S. Typhimurium strain to re-focus the pigâ€™s immune response from serovar-specific antigens to conserved antigens during vaccination against Salmonella, thereby providing cross-protection against multiple Salmonella serovars.
3) Classify the porcine gene expression differences between low and high shedders of Salmonella during colonization.
4) Compare the gastrointestinal microbial communities of pigs before, during and after Salmonella colonization to assess correlations with Salmonella shedding status in the pigs.
Salmonella enterica serovar Typhimurium-infected pigs with different shedding levels exhibit distinct clinical, peripheral cytokine and transcriptomic immune response phenotypes
Knetter SM, Bearson SM, Huang TH, Kurkiewicz D, Schroyen M, Nettleton D, Berman D, Cohen V, Lunney JK, Ramer-Tait AE, Wannemuehler MJ, Tuggle CK.
Innate Immun. 2014 Mar 14. [Epub ahead of print]
TLR4 single nucleotide polymorphisms (SNPs) associated with Salmonella shedding in pigs
Kich JD, Uthe JJ, Benavides MV, Cantao ME, Zanella R, Tuggle CK, Bearson SM.
J Appl Genet. 2014 Feb 25. [Epub ahead of print]
Polynucleotide phosphorylase (PNPase) is required for Salmonella enterica serovar Typhimurium colonization in swine
Bearson SM, Bearson BL, Lee IS, Kich JD.
Microb Pathog. 2013 Oct 11;65C:63-6.
Tetracycline accelerates the temporally-regulated invasion response in specific isolates of multidrug-resistant Salmonella enterica serovar Typhimurium
Brunelle BW, Bearson SM, Bearson BL.
BMC Microbiol. 2013 Sep 11;13(1):202.
Profiling the gastrointestinal microbiota in response to Salmonella: low versus high Salmonella shedding in the natural porcine host
Bearson SM, Allen HK, Bearson BL, Looft T, Brunelle BW, Kich JD, Tuggle CK, Bayles DO, Alt D, Levine UY, Stanton TB.
Infect Genet Evol. 2013 Jun;16:330-40.
Nucleotide and phylogenetic analyses of the Chlamydia trachomatis ompA gene indicates it is a hotspot for mutation
Brunelle BW, Sensabaugh GF.
BMC Res Notes. 2012 Jan 20;5:53.
Transcriptomic analysis of multidrug-resistant Salmonella enterica serovar Typhimurium isolates that exhibit a tetracycline-induced invasion phenotype - (Abstract Only)
Brunelle, B.W., Bearson, S.M., Bearson, B.L. 2013. Transcriptomic analysis of multidrug-resistant Salmonella enterica serovar Typhimurium isolates that exhibit a tetracycline-induced invasion phenotype [abstract]. Molecular Genetics of Bacteria and Phage Meeting. p. 221.
Tlr4 Single Nucleotide Polymorphisms (Snps) Associated with Salmonella Shedding in Pigs - (Abstract Only)
Kich, J.D., Uthe, J.J., Benavides, M.V., Cantao, M.E., Zanella, R., Tuggle, C.K., Bearson, S.M. 2013. TLR4 single nucleotide polymorphisms (SNPs) associated with Salmonella shedding in pigs [abstract]. Paper No. 2164.
Tetracycline can induce the expression of invasion factors in multidrug-resistant Salmonella during early-log phase - (Abstract Only)
Brunelle, B.W., Bearson, S.M., Bearson, B.L. 2012. Tetracycline can induce the expression of invasion factors in multidrug-resistant Salmonella during early-log phase [abstract]. American Society for Microbiology General Meeting, June 16-19, 2012, San Francisco, California. Paper No. 1606.
Profiling the gastrointestinal microbiota in response to Salmonella: low versus high Salmonella shedding in the porcine host - (Abstract Only)
Bearson, S.M., Allen, H.K., Bearson, B.L., Looft, T.P., Brunelle, B.W., Kich, J.D., Bayles, D.O., Alt, D.P., Levine, U.Y., Stanton, T.B. 2012. Profiling the gastrointestinal microbiota in response to Salmonella: low versus high Salmonella shedding in the porcine host [abstract]. American Society for Microbiology General Meeting, June 16-19, 2012, San Francisco, California. p. 3150.