【摘要】 采用红细胞凝集试验 (HA)和凝集抑制试验 (HIA) ,对大肠杆菌、乳杆菌和双歧杆菌凝集素活性和化学性质进行了研究。HA结果表明 ,在 3种菌的细胞表面均存在凝集素并能够凝集猪和兔红细胞 ,且乳杆菌对 2种红细胞的凝集活性较高。细菌经化学试剂 (高碘酸钠、SDS、EDTA、LiCl)和酶 (蛋白酶、胰蛋白酶、脂酶 )处理后的HA结果表明 ,凝集素为糖蛋白类物质。HIA的结果表明 ,大肠杆菌的凝集反应可被甘露糖 (1.43mg/ml)、半乳糖(2 .5 3mg/ml)抑制 ;乳杆菌的凝集反应可被鼠李糖 (1.45mg/ml)、甲基 β 呋喃半乳糖苷 (3.75mg/ml)抑制 ;双歧杆菌的凝集反应可被鼠李糖 (2 .2mg/ml)、半乳糖 (2 .3mg/ml)、墨角藻糖 (3.14mg/ml)、阿拉伯糖 (3.44mg/ml)、甘露糖 (3.74mg/ml)和果糖 (3.98mg/ml)抑制。兔红细胞经神经氨酸酶修饰后可显著提高 3种菌的凝集素活性 ,而经 β 半乳糖苷酶修饰后大肠杆菌对其凝集活性完全丧失 ,而后二者的凝集活性不受影响。上述结果提示 ,3种菌对红细胞的凝集反应是以细菌表面的糖蛋白类物质特异性识别红细胞表面的受体的方式来介导的。更多还原

【Abstract】 The lectin activity and chemical characteristics of Escherichia coli, Lactobacilli spp. and Bifidobacteria spp. of porcine ceceal mucosal layer origin was studied based on hemagglutination (HA) and HA inhibition assays. The results of HA showed that although all the bacterial strains were able to agglutinate pig and rabbit erythrocytes, much higher HA titers were consistently observed for Lactobacilli spp. than that for E.coli or Bifidobacteria spp. Glycoproteins were responsible for the HA of these microorganisms, because a remarkable reduction of HA titers occurred due to treatment of E.coli and Lactobacilli with protease, trypsin, SDS or LiCl and that of Bifidobacteria spp. with protease, trypsin, periodate, SDS, or LiCl. There were no significant effect on the HA titers of the three groups of bacteria after the treatment with lipase. The results of HIA assays showed that hemagglutination of E.coli was strongly inhibited by D(+)-mannose and D(+)-galactose; that of Lactobacilli by α-L-rhamnose and methyl-β-galactopyranoside; that of Bifidobacteria by D(+)-galactose, α-L-rhamnose, α-L-fucose, L(+)-arabinose, D(+)-mannose, D(-)-fructose at a relatively low concentration ( 1.43-3.75 mg/ml). HA activity of the three bacterial strains could be enhanced by modification of rabbit erythrocytes with neuraminidase, and HA activity of E.coli was abolished after treatment with β-galactosidase. All the results prompted us that it was the glycoproteinous substances surrounding the surface of the bacterial cells that were responsible for the adhesion of these microorganisms by recognizing the specific receptors on the red blood cell.更多还原