Response When Inoculated in Bovine In Vitro Fecal Microbial Consortia Incubations in the Presence of Metabolic Inhibitors.

Infection with the foodborne pathogen is the leading bacterial cause of human foodborne illness in the United States. The objectives of this experiment were to test the hypothesis that mixed microbial populations from the bovine rumen may be better at excluding than populations from freshly voided feces and to explore potential reasons as to why the rumen may be a less favorable environment for than feces. In an initial experiment, cultures inoculated without or with freshly collected bovine rumen fluid, bovine feces or their combination were cultured micro-aerobically for 48 h.

Immunogenic inhibition of prominent ruminal bacteria as a means to reduce lipolysis and biohydrogenation activity in vitro.

Lipolysis and biohydrogenation in ruminal animals promote the accumulation of saturated fatty acids in their meat and milk. Antibodies were generated against key ruminal lipase contributors Anaerovibrio lipolyticus, Butyrivibrio fibrisolvens, Propionibacterium avidum and acnes. An anti-Pseudomonas lipase antibody was generated to determine if an antibody against a purified protein would be more effective.

Comparison of anti-Campylobacter activity of free thymol and thymol-β-D-glucopyranoside in absence or presence of β-glycoside-hydrolysing gut bacteria.

Thymol is a natural product that exhibits antimicrobial activity in vitro but in vivo results indicate that absorption within the proximal alimentary tract precludes its delivery to the distal gut. Presently, the anti-Campylobacter activity of thymol was compared against that of thymol-β-D-glucopyranoside, the latter being resistant to absorption. When treated with 1 mM thymol, Campylobacter coli and jejuni were reduced during pure or co-culture with a β-glycoside-hydrolysing Parabacteroides distasonis.

Ex vivo absorption of thymol and thymol-β-D-glucopyranoside in piglet everted jejunal segments.

Food-producing animals are reservoirs of Campylobacter, a leading bacterial cause of human foodborne illness. The natural product thymol can reduce the survivability of Campylobacter, but its rapid absorption in the proximal gastrointestinal tract may preclude its use as a feed additive to reduce intestinal colonization of these pathogens. This work examined the ex vivo absorption of thymol and thymol-β-d-glucopyranoside in everted porcine jejunal segments, as the latter was hypothesized to be more resistant to absorption.

Bactericidal effect of hydrolysable and condensed tannin extracts on Campylobacter jejuni in vitro.

Strategies are sought to reduce intestinal colonisation of food-producing animals by Campylobacter jejuni, a leading bacterial cause of human foodborne illness worldwide. Presently, we tested the antimicrobial activity of hydrolysable-rich blackberry, cranberry and chestnut tannin extracts and condensed tannin-rich mimosa, quebracho and sorghum tannins (each at 100 mg/mL) against C. jejuni via disc diffusion assay in the presence of supplemental casamino acids.

Effect of thymol or diphenyliodonium chloride on performance, gut fermentation characteristics, and campylobacter colonization in growing swine.

Food producing animals can be reservoirs of Campylobacter, a leading bacterial cause of human foodborne illness. Campylobacter spp. utilize amino acids as major carbon and energy substrates, a process that can be inhibited by thymol and diphenyliodonium chloride (DIC).

Escherichia coli O157:H7 populations in ruminants can be reduced by orange peel product feeding.

Foodborne pathogenic bacteria such as Escherichia coli O157:H7 are threats to the safety of beef. Citrus peel and dried orange pulp are by-products from citrus juice production that have natural antimicrobial effects and are often incorporated into least-cost ration formulations for beef and dairy cattle. This study was designed to determine if orange peel and pulp affected E.

Effects of feed-supplementation and hide-spray application of two sources of tannins on enteric and hide bacteria of feedlot cattle.

Pathogenic bacteria attached to the hide or shed in the feces of cattle at slaughter can contaminate carcasses intended to be processed for human consumption. Therefore, new pre-harvest interventions are needed to prevent the carriage and excretion of foodborne pathogens in cattle presented to the processing plant. The objectives of this study were to examine the antimicrobial effects of hydrolysable tannin-rich chestnut and condensed tannin-rich mimosa extracts on bacterial indicators of foodborne pathogens when applied as a hide-intervention and as a feed additive to feedlot cattle.

Effect of nitroethane, dimethyl-2-nitroglutarate and 2-nitro-methyl-propionate on ruminal methane production and hydrogen balance in vitro.

Ruminal methanogenesis is considered a digestive inefficiency that results in the loss of 2-12% of the host's gross energy intake and contributes nearly 20% to the United States annual CH(4) emissions. Presently, the effects of the known CH(4) inhibitor, nitroethane, and two synthetic nitrocompounds, dimethyl-2-nitroglutarate and 2-nitro-methyl-propionate, on ruminal CH(4) production and fermentation were evaluated in vitro. After 24 h incubation at 39 degrees C under 100% CO(2), ruminal fluid cultures treated with 2.

Effect of nitroethane and nitroethanol on the production of indole and 3-methylindole (skatole) from bacteria in swine feces by gas chromatography.

Indole and 3-methylindole (skatole) are odor pollutants in livestock waste, and skatole is a major component of boar taint. Skatole causes pulmonary edema and emphysema in ruminants and causes damage to lung Clara cells in animals and humans. A gas chromatographic method that originally used a nitrogen-phosphorus detector to increase sensitivity was modified resulting in an improved flame ionization detection response for indole and skatole of 236% and 207%, respectively.

Effect of chlorate, molybdate, and shikimic acid on Salmonella enterica serovar Typhimurium in aerobic and anaerobic cultures.

Experiments were conducted to determine factors that affect sensitivity of Salmonella enterica serovar Typhimurium to sodium chlorate (5mM). In our first experiment, cultures grown without chlorate grew more rapidly than those with chlorate. An extended lag before logarithmic growth was observed in anaerobic but not aerobic cultures containing chlorate.

Prevalence and concentration of Campylobacter in rumen contents and feces in pasture and feedlot-fed cattle.

Campylobacter are important human foodborne pathogens known to colonize the gastrointestinal tract of cattle. The incidence of Campylobacter in cattle may be seasonal and may vary among age groups and type (beef versus dairy). Less is known about other factors that could influence the prevalence, colonization site, and shedding of Campylobacter in cattle.

Effects of select nitrocompounds on in vitro ruminal fermentation during conditions of limiting or excess added reductant.

Ruminal methane (CH(4)) production results in the loss of up to 12% of gross energy intake and contributes nearly 20% of the United States' annual emission of this greenhouse gas. We report the effects of select nitrocompounds on ruminal fermentation after 22 h in vitro incubation (39 degrees C) with or without additions of hydrogen (H(2)), formate or both. In incubations containing no added reductant, CH(4) production was inhibited 41% by 2-nitro-1-propanol (2NPOH) and >97% by 3-nitro-1-propionic acid (3NPA), nitroethane (NE) and 2-nitroethanol (2NEOH) compared to non-treated controls and H(2) did not accumulate.

Effects of nitroethane and monensin on ruminal fluid fermentation characteristics and nitrocompound-metabolizing bacterial populations.

Nitroethane is a potent inhibitor of ruminal CH 4 production, a digestive inefficiency resulting in the loss of 2-15% of a ruminant's gross energy intake and an important emission source of this greenhouse gas. To assess the effect of nitroethane on methanogenesis and characterize ruminal adaptation observed with low treatment doses to this inhibitor, ruminal microbes were cultured in vitro with supplements of water (controls), 4.5 and 9 mM nitroethane, and 0.