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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #338427

Research Project: Ecological Reservoirs and Intervention Strategies to Reduce Foodborne Pathogens in Cattle and Swine

Location: Food and Feed Safety Research

Title: Antagonistic effects of lipids against the bactericidal activity of thymol-beta-D-glucopyranoside

Author
item Anderson, Robin
item Levent, Gizem - Istanbul University
item Petrujkic, Branko - University Of Belgrade
item Ciftcioglu, Gurhan - Istanbul University
item Harvey, Roger
item Hume, Michael
item He, Louis - Haiqi
item Genovese, Kenneth - Ken
item Beier, Ross
item Swaggerty, Christina - Christi
item Callaway, Todd
item Nisbet, David - Dave

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The gut of food-producing animals is a reservoir for zoonotic pathogens. Thymol is bactericidal against Salmonella, E. coli, and Campylobacter, but its rapid absorption from the proximal gut reveals a need for protective technologies to deliver effective concentrations to the lower gut where the pathogens mainly colonize. Thymol-beta-D-glucopyranoside (hereafter named beta-D-thymol) is resistant to absorption in everted jejunal segments because of its beta-glycosidic bond and thus could be used as a prebiotic, being resistant to absorption and degradation in the proximal gut but hydrolysable by microbial beta-D-thymol-hydrolyzing enzymes in the distal gut. Results from in vitro dose titration studies have identified efficacious doses of beta-D-thymol against Salmonella, E. coli, and Campylobacter during culture with porcine gut bacteria, with concentrations of beta-D-thymol needed to achieve efficacious reductions of Salmonella or E. coli being 6 to 9 times higher than that (1 mM) needed to effectively kill Campylobacter species. The increased susceptibility of Campylobacter to beta-D-thymol may be a consequence of its dependence on amino acid fermentation, as free thymol is thought to inhibit this activity. Oral administration of beta-D-thymol to pigs did not achieve significant reductions in cecal and rectal concentrations of Salmonella, E. coli, or Campylobacter. Among several possible hypotheses for the lack of activity in vivo, internal compartmentalization of beta-D-thymol by gut bacteria or its lipophilicity may sequester the beta-D-thymol away from hydrolytic enzymes, thus preventing the release of free thymol. In support of the latter hypothesis, we found that the bactericidal effect of beta-D-thymol (6 mM) against Salmonella Typhimurium and E. coli K88 (4.50 and 4.69 log10-fold reductions in CFU, respectively), achieved after 24 h in vitro culture with porcine fecal microbes, was diminished (P < 0.05; SEM = 0.448 and 0.497; respectively) more than 68 and 91% by 3% (wt/vol) added vegetable or olive oil (n = 3 cultures/treatment). Additional research is warranted to learn how to overcome obstacles diminishing bactericidal activity of beta-D-thymol in the lower gastrointestinal tract.