乳杆菌竞争性抑制两种病原菌粘附上皮细胞的研究

Study of the Lactobacillus Competitive Inhibition of Two Kinds of Pathogenic Bacteria Adhesion to Jejunum Epithelial Cells

【目的】研究嗜酸乳杆菌(LAB1)在体外模拟预防和治疗条件下,竞争性抑制致病性大肠杆菌(Escherichia coli,E.coli)和沙门氏菌(Salmonella choleraesuis,S.cho)对仔猪空肠上皮细胞系(IPEC-J2)的粘附作用。【方法】用LAB1预处理IPEC-J2后再用E.coli或S.cho攻毒为模拟预防实验;用E.coli或S.cho先攻毒IPEC-J2后再用LAB1处理为模拟治疗试验。提取粘附后的3种菌及IPEC-J2的DNA,使用文献记载和自行设计的引物,利用实时荧光定量PCR方法,量化检测LAB1与E.coli、S.cho之间的竞争性粘附率。【结果】在模拟治疗试验中,在高(1.0×109CFU)、中(1.0×108CFU)、低(1.0×107CFU)3种浓度的LAB1处理条件下,能显著抑制高、中浓度S.cho对IPEC-J2的粘附(P<0.05);在模拟预防试验中,相同浓度的LAB1能显著抑制相同浓度的S.cho对IPEC-J2的粘附(P<0.05)。在模拟预防和治疗试验中,3种浓度LAB1均能显著抑制低浓度E.coli对IPEC-J2的粘附(P<0.05),高浓度LAB1能显著抑制高、中浓度E.coli对IPEC-J2的粘附(P<0.05)。【结论】在体外试验条件下,LAB1对E.coli及S.cho粘附IPEC-J2有竞争性抑制作用。在模拟预防和治疗试验中,LAB1对E.coli及S.cho粘附IPEC-J2的竞争性抑制作用效果有所不同。

【Objective】Lactobacillus acidlophilus（separated and identified by the authors’ laboratory,tentatively named LAB1） competitive inhibition of pathogenic Escherichia coli and Salmonella choleraesuis adhesion to jejunum epithelial cells（IPEC-J2） in the conditions of prevention and treatment in vitro was studied.【Method】 IPEC-J2 cells were pretreated with LAB1 and then exposed to E.coli or S.choleraesuis which were used as simulated prevention trials.IPEC-J2 cells were exposed to E.coli or S.choleraesuis and then treated with LAB1 which were used as simulated treatment trials.Cells and three kinds of bacterial DNA were purified after bacteria adhesion to IPEC-J2 cells.The relative amount of bacteria attached was determined by amplification of the special gene relative to documented and self-designed primers,in the presence of SYBR Green.【Result】In the simulated treatment experiment,three concentrations of LAB1 significantly inhibited 108CFU S.choleraesuis adherence to IPEC-J2 cells（P〈0.05）.In the simulated prevention trial,the same concentrations of LAB1 significantly inhibited S.cho leraesuisadhesion of IPEC-J2 cells（P〈0.05）.Simulation of the prevention and treatment trials,three concentrations of LAB1 significantly inhibited the 107CFU of E.coli adhesion to IPEC-J2 cells（P〈0.05）,and 109CFU LAB1 significantly inhibited the adhesion of the 109CFU of E.coli to IPEC-J2 cells（P〈0.05）.【Conclusion】LAB1 have competitive inhibition on E.coli and S.cho adhesion to IPEC-J2 cells in vitro,the effect of LAB1 inhibition on E.coli and S.choleraesuis adhesion to IPEC-J2 cells in simulation of the prevention and treatment experiments is different.