ARS | Publication request: Low Level Nitrate Or Nitroethane Preconditioning Enhances the Bactericidal Effect of Suboptimal Experimental Chlorate Treatment Against Salmonella in Swine

Submitted to: Proceedings Of Allen D Leman Swine Conference
Publication Acceptance Date: August 20, 2004
Publication Date: September 20, 2004
Citation: Anderson, R.C., Jung, Y., Genovese, K.J., Mcreynolds, J.L., Callaway, T.R., Edrington, T.S., Harvey, R.B., Nisbet, D.J. 2004. Low Level Nitrate Or Nitroethane Preconditioning Enhances The Bactericidal Effect Of Suboptimal Experimental Chlorate Treatment Against Salmonella In Swine. Proceedings Of Allen D. Leman Swine Conference. 31(SUPPL.):49.

Technical Abstract: An experimental chlorate product (ECP) that targets the respiratory nitrate reductase enzyme of bacteria such as Salmonella has shown promising results in reducing concentrations of these bacteria in the gut of food animals. Because expression of the target enzyme is induced by nitrate, we conducted a study to see if short-duration, low level nitrate or nitroethane preconditioning would enhance the ability of ECP to kill these bacteria. Finished pigs were randomly allocated to one of the following treatments; basal diet control (n = 6), 1 d nitrate preconditioning (n = 4), 2 d nitrate preconditioning (n = 6), 2 d nitroethane preconditioning (n = 6), ECP alone (n = 6), 1 d nitrate preconditioning plus ECP (n =4), 2 day nitrate preconditioning plus ECP (n = 6) or 2 d nitroethane preconditioning plus ECP (n = 6). Sodium nitrate and nitroethane (at 0.01 and 0.4% wt/wt, respectively) were mixed in the feed before feeding. Preconditioning treatments were fed before provision of the last day's meals containing 0 or 1% ECP (wt/wt). In order to enhance our ability to measure effects of preconditioning, ECP was fed at half the efficacious dose. Pigs were challenged per os with 20,000,000,000 CFU Salmonella typhimurium 6 d before preconditioning. Pigs were euthanized the day after provision of the last day's meal and gut contents were collected and cultured for Salmonella. Preconditioning or ECP treatment alone did not reduce Salmonella concentrations. Both the 2-day nitrate preconditioning plus ECP and the 2-day nitroethane plus ECP treatments reduced (P < 0.05) gut Salmonella concentrations. These results confirm that nitrate or nitroethane preconditioning enhance the bactericidal activity of ECP.