Characterization of inhibitory factors of lactic acid bacteria against gastrointestinal pathogens

本研究的目的是阐明罗伊氏乳杆菌和加氏乳杆菌竞争性排除胃肠道病原体的能力。在前人研究的基础上，本研究首次测定了L. reuteri JCM 1081与硫苷脂的硫酸化糖链结合，硫苷脂被认为是幽门螺杆菌的受体部分。潜在的粘附因子，Ef-Tu表达为重组蛋白，然后进行动力学研究。Ef-Tu对硫苷脂有很强的亲和性，在pH4.0时能很好地粘附在细胞表面，而在pH6.0时不能。检查先前选择的用于竞争性排除雏鸡中空肠弯曲杆菌81-176的gasseri TM 333。雏鸡每天口服L。gasseri TM 333经口感染C. jejuni81 - 176。gasseri TM 333对盲肠定殖的抑制率为98%;空肠81- 176。gasseri TM 333有效地抑制鸡盲肠的弯曲杆菌定殖。

The goal of our study was to elucidate the capacity of the Lactobacillus reuteri and Lactobacillus gasseri to competitively exclude gastrointestinal pathogens. On the basis of the previous results, this study was firstly conducted to determine the adhesion factor of L. reuteri JCM1081 to the sulfated sugar chains of sulfatide, which was recognized as a receptor moiety of Helicobacter pylori. The potential adhesion factor, Ef-Tu was expressed as a recombinant protein followed by kinetics studies. Ef-Tu of the strain was shown to be a high affinity for sulfatide and to be retained tightly on the cell surface at pH 4.0 but not to pH6.0.The findings strongly suggested that Ef-Tu is a novel adhesion factor the sulfated sugar chains of sulfatide to in Lactobacillus strains.Secondly, the capacity of fibronectin-adherent L. gasseri TM333 selected previously to competitively exclude Campylobacter jejuni 81-176 in chicks was examined. Chicks were given daily oral doses of L. gasseri TM333 for 7 days after oral infection with C. jejuni 81-176.The chicks treated with L. gasseri TM333 showed 98% inhibition of cecum colonization by C. jejuni 81-176.The findings indicate the fibronectin-adherent L. gasseri TM333 effectively inhibited Campylobacter colonization of the chick cecum.