【摘要】 目的对益生菌—枯草杆菌芽孢进行耐性评估,为研制口服枯草杆菌芽孢载体疫苗奠定基础。方法采用耗竭法,DSM培养基长时间振荡培养(24h)获得芽孢,使用pH2.0盐酸胃蛋白酶液模拟胃液,胆酸盐、胰液素混合液模拟肠液,对枯草杆菌芽孢进行体外耐受实验。结果在DSM培养基中,80%～90%的枯草杆菌WB600可形成芽孢,每升DSM液所生成芽孢约1×1011。在模拟胃液中1h后,仅0.0024%枯草杆菌WB600繁殖体细菌仍成活,大肠杆菌JM109活力完全丧失,而枯草杆菌芽孢基本不受影响,93.3%仍成活。在模拟小肠环境中3h后,枯草杆菌WB600繁殖体细菌活力显著降低(仅0.0013%存活),枯草杆菌芽孢基本不受影响(92%仍存活),而大肠杆菌JM109有一定量的增殖。结论枯草杆菌芽孢能耐受模拟胃肠道环境,有望成为新型的口服疫苗载体。更多还原

【Abstract】 Objective To evaluate the resistance of probiotic Bacillus subtilis spores in gastrointestinal tract environment,and to provide the basis for developing oral vaccine using B. subtilis spores. Methods Sporulation was induced in Difco Sporulation Medium (DSM) by the exhaustion method. Resistance to simulated gastric juice (pepsin,pH 2.0) and small intestinal fluid (bile salts and pancreatin) was then determined. Results 80% to 90% of B. subtilis WB600 formed spores in DSM culture medium. An estimated concentration of 1×1011 spores/L was obtained. Under the experimental condition that killed 100% of E.coli JM109,the percentage of surviving vegetative cells and spores in simulated gastric juice was 0.0024% and 93.3%,respectively. In simulated small intestine fluid,viability of the vegetative cells was significantly reduced (only 0.0013% alive). However,in simulated small intestine fluid,the viability of spores was 92% and the growth of E. coli was also increased in this medium. Conclusion B. subtilis spores may survive in gastrointestinal tract,and it may further be developed as an oral vaccine vehicle.更多还原