The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity...The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity are expected to be beneficial for reducing diarrhoea caused by pathogens in weaned piglets, the effects of such materials on porcine intestinal cells have not been investigated in detail. Therefore, this work evaluated the immunoregulatory functions of microbial feed materials in porcine intestinal immune and epithelial cells. Porcine immune cells isolated from Peyer’s patches and mesenteric lymph nodes were stimulated with six different feed materials containing microorganisms, and evaluated for lymphocyte mitogenicity and cytokine inductions. In addition, porcine intestinal epithelial cells were stimulated with the materials before treatment with heat-killed enterotoxigenic Escherichia coli (ETEC), and analyzed for the proinflammatory cytokine expressions. The material containing Bifidobacterium thermophilum significantly augmented lymphocytes’ mitogenicity and also induced a high expression of IL-2, IL-6 and IFN-γ in immune cells, and inhibited ETEC-induced overexpression of IL-6 and IL-8 via regulation of Toll-like receptor signaling. These results suggest that this feed material stimulates intestinal epithelial and immune cells to exert immunoregulation, suggesting that this feed is expected to contribute to promoting the health of piglets without using antimicrobial feed materials.展开更多
Control of within-herd transmission of Salmonella is important for reducing the prevalence of this organism on pig farms and for preventing Salmonella-contamination of pork. At the farm level, understanding the within...Control of within-herd transmission of Salmonella is important for reducing the prevalence of this organism on pig farms and for preventing Salmonella-contamination of pork. At the farm level, understanding the within-herd transmission of Salmonella can lead to more effective control. Salmonella infection is dependent on the inoculation dose;hence, quantitative evaluation of Salmonella shed in feces would provide useful information for developing effective measures. In this study, to reproduce and evaluate the number of Salmonella shed in diarrhea, loose stools, and normal feces, weaned pigs were inoculated with 3.2 × 109, 3.2 × 107, and 3.2 × 105 cfu of Salmonella Typhimurium, respectively. The number of S. Typhimurium shed in the feces peaked within 1 week post-inoculation in every group and the most amount of diarrhea and loose stools were observed within 2 weeks post-inoculation. Diarrhea occurred 10 times (six pigs), and loose stools were observed 25 times (11 pigs). The average concentration of S. Typhimurium shed in diarrhea, loose stools, and normal feces was 1.0 × 108, 1.6 × 104, and 7.1 × 101 cfu/g feces, respectively. These data suggest that diarrhea and loose stools are significant sources of within-herd transmission of Salmonella. Moreover, as some of the normal feces contained >1.0 × 106 cfu/g of S. Typhimurium, even normal feces could be a source of within-herd transmission of Salmonella. At Salmonella-positive farms, reduction of the amount of Salmonella shed even in normal feces would lead to better control of within-herd transmission of Salmonella. These data can contribute to the control of within-herd transmission of Salmonella, particularly during the weaning period.展开更多
文摘The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity are expected to be beneficial for reducing diarrhoea caused by pathogens in weaned piglets, the effects of such materials on porcine intestinal cells have not been investigated in detail. Therefore, this work evaluated the immunoregulatory functions of microbial feed materials in porcine intestinal immune and epithelial cells. Porcine immune cells isolated from Peyer’s patches and mesenteric lymph nodes were stimulated with six different feed materials containing microorganisms, and evaluated for lymphocyte mitogenicity and cytokine inductions. In addition, porcine intestinal epithelial cells were stimulated with the materials before treatment with heat-killed enterotoxigenic Escherichia coli (ETEC), and analyzed for the proinflammatory cytokine expressions. The material containing Bifidobacterium thermophilum significantly augmented lymphocytes’ mitogenicity and also induced a high expression of IL-2, IL-6 and IFN-γ in immune cells, and inhibited ETEC-induced overexpression of IL-6 and IL-8 via regulation of Toll-like receptor signaling. These results suggest that this feed material stimulates intestinal epithelial and immune cells to exert immunoregulation, suggesting that this feed is expected to contribute to promoting the health of piglets without using antimicrobial feed materials.
文摘Control of within-herd transmission of Salmonella is important for reducing the prevalence of this organism on pig farms and for preventing Salmonella-contamination of pork. At the farm level, understanding the within-herd transmission of Salmonella can lead to more effective control. Salmonella infection is dependent on the inoculation dose;hence, quantitative evaluation of Salmonella shed in feces would provide useful information for developing effective measures. In this study, to reproduce and evaluate the number of Salmonella shed in diarrhea, loose stools, and normal feces, weaned pigs were inoculated with 3.2 × 109, 3.2 × 107, and 3.2 × 105 cfu of Salmonella Typhimurium, respectively. The number of S. Typhimurium shed in the feces peaked within 1 week post-inoculation in every group and the most amount of diarrhea and loose stools were observed within 2 weeks post-inoculation. Diarrhea occurred 10 times (six pigs), and loose stools were observed 25 times (11 pigs). The average concentration of S. Typhimurium shed in diarrhea, loose stools, and normal feces was 1.0 × 108, 1.6 × 104, and 7.1 × 101 cfu/g feces, respectively. These data suggest that diarrhea and loose stools are significant sources of within-herd transmission of Salmonella. Moreover, as some of the normal feces contained >1.0 × 106 cfu/g of S. Typhimurium, even normal feces could be a source of within-herd transmission of Salmonella. At Salmonella-positive farms, reduction of the amount of Salmonella shed even in normal feces would lead to better control of within-herd transmission of Salmonella. These data can contribute to the control of within-herd transmission of Salmonella, particularly during the weaning period.
