细胞壁缺陷对白喉棒状杆菌致病性影响的研究

检测白喉棒状杆菌稳定L型对动物的致病性,探讨细胞壁缺陷对白喉棒状杆菌致病性的影响及其可能的分子机制。采用氨苄青霉素在非高渗培养基内诱导并获得产毒性白喉棒状杆菌稳定L型纯培养物。收集白喉棒状杆菌稳定L型纯培养物及其代谢产物,将收集的高于细菌型10 000倍浓度的白喉棒状杆菌稳定L型纯培养物及其代谢产物皮内注射家兔,观察局部注射部位皮肤或全身的病理改变。分别采用对流免疫电泳(CIEP)和SDS-不连续聚丙烯酰胺凝胶电泳(SDS-PAGE)检测白喉棒状杆菌稳定L型可溶性代谢产物中的白喉毒素蛋白质。结果显示,白喉棒状杆菌稳定L型不能引起动物局部或全身发生异常表现,在其可溶性代谢产物中并未检测到白喉毒素蛋白质。提示细胞壁缺陷变异可影响白喉棒状杆菌产生白喉毒素蛋白质,从而使其丧失了产生外毒素致病的作用。

Effect of Cell Wall Defect on Pathogenicity of Corynebacterium diphtheriae

Pathogenicity of stable L-form Corynebacterium diphtheriae(CD) against animals was tested.And the effect of cell wall defect on its pathogenicity and the possible molecular mechanism were investigated.L-forms CD were induced with ampicilin in a non-high osmotic medium and then its pure culture of stable L-forms were isolated and collected.Rabbits were injected intradermally with the pure culture and its metabolites at 10 000 times of concentration to observe the local injected part of skin and the pathogenic changes of the animal whole body.Diphtherotoxin in the soluble metabolites of the stable L-form CD was detected with CIEP and SDS-PAGE.The results showed that the stable L-form CD could not cause abnormal appearance on local and/or the whole body.And no diphtherotoxin was detected in its soluble metabolites indicating that cell wall defect might affect the production of diphtherotoxin,therefore lost its pathogenic role in exotoxin production.