HUS development associated with bacterial infection and prevention against HUS

脆弱类杆菌菌株TDP 101是从一名患有出血性结肠炎并随后出现HUS的两岁女童粪便中分离到的，我们研究了该菌株的致病性及其神经氨酸酶活性在HUS诱导中的作用.脆弱B.fragilis菌株TDP101在家兔和小鼠体内均具有肠致病性.该菌株的无细胞提取物对Vero细胞和HEL细胞具有细胞毒性，如肠出血性大肠杆菌菌株KY1101的培养上清液所示。在Vero细胞和HEL细胞中诱导形态学变化的最高稀释度的倒数对于脆弱B. TDP 101为640和160，对于大肠杆菌KY1101.3为640和640。脆弱B.fragilis菌株TDP101的培养上清对鸡、牛、兔、马、羊的红细胞有较弱的溶血活性.腹腔注射脆弱B.fragilis菌株TDP 101诱导小鼠溶血性贫血和血小板减少，但不诱导肾衰竭。注射后1天在心脏血液中检测到给药细菌，但7天后未检测到。将编码神经氨酸酶基因nanH的质粒pKK 105导入单形拟杆菌，获得了一株神经氨酸酶产生菌。单形B.uniformis菌株BU 1001（pTKK 105）的神经氨酸酶活性与脆弱B.在较长的时间内检测到更多的细菌，

Bacteroides fragilis strain TDP101 was isolated from the feces of a two-year-old female suffered from hemorrhagic colitis arid subsequently HUS.We investigated the pathogenicity of this strain and the role of its neuraminidase activity in the HUS induction.1. B.fragilis strain TDP101 was enterotoxigenic in rabbit and mice.2. A cell free extract of this strain was cytotoxic for Vero cell and HEL cells as shown by the culture supernatant of enterohemorrhagic E.coil strain KY1101. The reciprocals of highest dilution inducing morphological change in Vero cells and HEL cells were 640 and 160 with B.fragilis TDP101, and 640 and 640 with E.coli KY1101.3. A culture supernatant of B.fragilis strain TDP101 showed weak hemolytic activity for red blood cells of chicken, bovine, rabbit, horse and sheep.4. Intraperitoneal injection of B.fragilis strain TDP101 induced hemolytic anemia and thrombocytopenia in mice but not renal failure. Administrated bacteria were detected in the heart blood 1 day after injection but not after 7 days.5. A neuraminidase-producinig strain of Bacteroides uniformis was constructed by introducing plasmid pKK105, which encodes a neuraminidase gene nanH from B.fragilis. B.uniformis strain BU1001(pTKK105) showed the same level of neuraminidase activity as B.fragilis strain TDP101, but no cytotoxicitv for Vero cells. More bacteria were detected for longer time in