Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 12/20/2007
Publication Date: 3/1/2007
Citation: Faith, N., Neudeck, B., Luchansky, J.B., Czuprynski, C. 2007. The role of gtcA in the Pathogenesis of Gastrointestinal Listeriosis. Proceedings pg.4. Interpretive Summary:
Technical Abstract: Serotype 4b strains of Listeria monocytogenes have been implicated in most large outbreaks of listeriosis. The reason for this relationship remains unclear. The gtcA gene is required for glycosylation of teichoic acid on serotype 4b L. monocytogenes. In this study, we investigated two different serotype 4b mutants of gtcA, which lack glucose and galactose residues on their teichoic acid, for their virulence when inoculated intragastrically into anesthetized A/J mice. Both gtcA mutant strains were recovered in lower numbers from the spleen, liver, ceca and gall bladders of mice inoculated i.g. than were their respective parent strains of L. monocytogenes. When the environment of the gastrointestinal tract was circumvented by inoculating mice i.v., both gtcA mutants were recovered in lower numbers than the parent strain from the liver, and one of the mutant strains was also recovered in lower numbers from the spleens of i.v. inoculated A/J mice. Likewise, the gtcA mutants of L. monocytogenes were less able to invade the Caco-2 human intestinal epithelial cell line in vitro, than the respective wild type parent strains. However, we noted no significant difference in CFU recovered from Caco-2 cells after a 24 hr incubation in vitro. These data suggest a role for gtcA in the pathogenesis of gastrointestinal listeriosis in mice. Future experiments will determine the effect of gtcA on the ability of L. monocytogenes to grow on ready to eat meat products, and mechanisms by which gtcA affects serotype 4b antigen expression and virulence.