|Byrd Ii, James - Allen|
|Genovese, Kenneth - Ken|
|Jung, Yong Soo|
Submitted to: United States Animal Health Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 10/20/2002
Publication Date: N/A
Technical Abstract: Salmonella and Escherichia coli O157:H7 are important pathogenic bacteria that can colonize the gut of food producing animals. These bacteria possess respiratory nitrate reductase activity. Since most strict anaerobic gut bacteria lack this activity, which by coincidence also catalyzes the intracellular reduction of the chlorate ion to cytotoxic chlorite, we hypothesized that chlorate may selectively kill Salmonella and E. coli, while not harming the beneficial gut bacteria. In support of this hypothesis, we found that Salmonella Typhimurium DT104 and E. coli O157:H7, but not total culturable anaerobes, were reduced in a dose dependent manner during in vitro incubation of buffered ruminal fluid supplemented with 1.25 and 5 mM chlorate, with reductions exceeding 100,000-fold CFU per ml. The proof of concept of this pathogen reduction technology was confirmed in vivo, with evidence demonstrating that drinking water administration reduced the incidences and concentrations of Salmonella colonization in crops or ceca of market age broilers and turkeys and reduced gut concentrations of Salmonella in finished pigs. We observed significant reductions in fecal E. coli concentrations following intraruminal addition of 2X ECP (5.4 vs 2.9 log10 CFU for control vs treated, respectively; X=15 mM active ion equivalents) to cattle (n=8) and >100-fold reductions in fecal E. coli O157:H7 concentrations in infected cattle (n=8) following 24 h access to water containing 7X ECP. Evidence from these and other studies with cattle indicate that strategies designed to optimize passage of chlorate through the rumen to the lower gut may be beneficial. Neither water intake nor animal well being were adversely affected by any of these treatments.