dc.description.abstract | Livestock producers need new technologies to maintain the optimal health and wellbeing of their animals while minimizing the risks of propagating and disseminating pathogenic and
antimicrobial-resistant bacteria to humans or other animals. Where possible, these interventions
should contribute to the efficiency and profitability of animal production to avoid passing costs on
to consumers. In this study, we examined the potential of nitroethane, 3-nitro-1-propionate, ethyl
nitroacetate, taurine and L-cysteinesulfinic acid to modulate rumen methane production, a digestive
inefficiency that results in the loss of up to 12% of the host’s dietary energy intake and a major
contributor of methane as a greenhouse gas to the atmosphere. The potential for these compounds
to inhibit the foodborne pathogens, Escherichia coli O157:H7 and Salmonella Typhimurium DT104,
was also tested. The results from the present study revealed that anaerobically grown O157:H7 and
DT104 treated with the methanogenic inhibitor, ethyl nitroacetate, at concentrations of 3 and 9 mM
had decreased (p < 0.05) mean specific growth rates of O157:H7 (by 22 to 36%) and of DT104 (by 16 to
26%) when compared to controls (0.823 and 0.886 h−1
, respectively). The growth rates of O157:H7 and
DT104 were decreased (p < 0.05) from controls by 31 to 73% and by 41 to 78% by α-lipoic acid, which
we also found to inhibit in vitro rumen methanogenesis up to 66% (p < 0.05). Ethyl nitroacetate was
mainly bacteriostatic, whereas 9 mM α-lipoic acid decreased (p < 0.05) maximal optical densities
(measured at 600 nm) of O157:H7 and DT104 by 25 and 42% compared to controls (0.448 and 0.451,
respectively). In the present study, the other oxidized nitro and organosulfur compounds were neither
antimicrobial nor anti-methanogenic. | sr |