Biotechnology Section, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
Res Vet Sci. 2012 Aug;93(1):74-81. doi: 10.1016/j.rvsc.2011.08.008. Epub 2011 Sep 9.
The activity of 240 bacterial isolates screened from the gastrointestinal tracts of native chickens were evaluated for use as a potential probiotic in food animal production in order to protect against animal diseases and reduce pathogenic contamination of human food products. In observing the antagonistic activity of 117 bacilli isolates, 10 of these isolates exhibited higher growth inhibition of seven foodborne pathogens, including Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Vibrio cholerae. Beneficial probiotic criteria from these isolates - which included non-pathogenicity, acid and bile salt tolerance, hydrophobicity, and adhesion to intestinal epithelial cells - exhibited that one isolate of NC11 had the most potential as a probiotic. 16S rRNA gene sequencing showed that this NC11 isolate was Bacillus subtilis. This B. subtilis NC11 was sensitive to all antibiotics and was not cytotoxic to intestinal epithelial cells. Reduction of S. Enteritidis attachment to the surfaces of intestinal epithelial cells via action of a cultured medium from B. subtilis NC11 was observed by scanning electron microscopy. B. subtilis NC11 cells, as well as the bacterial cultured medium or the cultured medium adjusted to pH 7, significantly inhibited S. Enteritidis invasion (P<0.01) of intestinal epithelial cells. This study indicates that B. subtilis NC11 has characteristics of a potential probiotic, and exhibits strong inhibition activity against S. Enteritidis infection to intestinal epithelial cells.
从本地鸡的胃肠道中筛选出 240 株细菌进行活性评估，以将其用作食品动物生产中的潜在益生菌，从而预防动物疾病并减少人类食品中病原污染。在观察 117 株杆菌分离物的拮抗活性时，其中 10 株分离物对包括肠炎沙门氏菌、鼠伤寒沙门氏菌、大肠杆菌、蜡样芽孢杆菌、金黄色葡萄球菌、单核细胞增生李斯特菌和霍乱弧菌在内的 7 种食源性病原体的生长抑制作用更高。从这些分离物中得出的有益益生菌标准 - 包括非致病性、耐酸和胆汁盐、疏水性和黏附于肠上皮细胞 - 表明 NC11 分离物最有潜力成为益生菌。16S rRNA 基因测序显示，该 NC11 分离物为枯草芽孢杆菌。枯草芽孢杆菌 NC11 对所有抗生素均敏感，且对肠上皮细胞无细胞毒性。通过扫描电子显微镜观察到枯草芽孢杆菌 NC11 的培养物可减少肠炎沙门氏菌附着在肠上皮细胞表面。枯草芽孢杆菌 NC11 细胞以及细菌培养物或调节至 pH7 的培养物均显著抑制肠炎沙门氏菌（P<0.01）侵袭肠上皮细胞。本研究表明，枯草芽孢杆菌 NC11 具有潜在益生菌的特性，对肠炎沙门氏菌感染肠上皮细胞具有强烈的抑制活性。
