【摘要】 目的研究肠侵袭性大肠埃希菌(EIEC)O抗原多糖(OPS)的特异性致病作用。方法提取并纯化大肠埃希菌O29———EIEC的脂多糖(LPS)亚单位分子———OPS进行体内外试验,观察其毒性作用并与LPS作对比。结果EIECOPS可引起HeLa细胞病变;致兔回肠袢肠黏膜出血,但不引起肠腔积液;电镜观察OPS致病变的HeLa细胞,明显可见细胞的超微病理损害。结论EIECOPS有特异的致病作用,与其LPS的内毒素作用不同;大肠埃希菌O29(致病菌株)OPS毒性作用比大肠埃希菌HB101(非致病菌株)OPS毒性强烈。更多还原

【Abstract】 Objective To investigate the specific pathogenesis of O-antigen polysaccharide(OPS) which is a subunit component of lipopolysaccharide(LPS) from enteroinvasive Escherichia coli. Methods The OPS was extracted and purified from Escherichia coli O29(enteroinvasive E.coli) strain. Effects of OPS, contrasted with the whole LPS molecule, were observed by in vitro experiments (HeLa cell culture) and in vivo experiments (rabbit ileal loop assay). Results It was revealed that the purified EIEC OPS alone cause cytopathic effect to HeLa cell, and that the OPS caused mucosal hemorrhage, but no fluid accumulation in ileal loop of rabbits. The scanning electron microscope and transmission electron microscope demonstrated the fine structures of cytopathic HeLa cell were damaged. Conclusion Escherichia coli O29 OPS might be one of the factors causing diarrhea and its mechanism was different from endotoxin reaction of LPS. Escherichia coli O29(pathogen) OPS showed a marked serious toxicity as compared with Escherichia coli HB101(nonpathogen) OPS.更多还原