Beta toxin is essential for the intestinal virulence of Clostridium perfringens type C disease isolate CN3685 in a rabbit ileal loop model
Beta toxin is essential for the intestinal virulence of Clostridium perfringens type C disease isolate CN3685 in a rabbit ileal loop model
复制标题
DOI：
10.1111/j.1365-2958.2007.06007.x
复制
发表时间：
2008-01-01
影响因子：
3.6
通讯作者：
McClane, Bruce A.
中科院分区：
文献类型：
--
作者：
Sayeed, Sameera;Uzal, Francisco A.;McClane, Bruce A.
C型产气荚膜梭菌分离株引起人类的坏死性肠炎以及家畜的肠炎和肠毒血症，通常在对数期生长期间产生（至少）β毒素（CPB）、α毒素（CPA）和产气荚膜梭菌溶素O（PFO）。为了帮助开发改进的疫苗和治疗方法，我们评估了这三种毒素对C型疾病分离株CN 3685肠道毒力的贡献。与自然C型感染相似，野生型CN 3685的对数期营养培养物在兔回肠袢中引起出血性坏死性肠炎。当使用TargeTron技术制备同基因毒素无效突变体时，即使CN 3685的双cpa/pfoA无效突变体在回肠袢中也保持毒性。然而，在该动物模型中，两个独立的cpb无效突变体的毒力完全减弱。互补的cpb突变恢复其CPB生产和肠道毒力。此外，野生型CN 3685与CPB中和单克隆抗体的预孵育使菌株对引起肠道病理学无毒性。最后，高度纯化的CPB再现了野生型CN 3685的肠损伤，并且通过将纯化的CPB与CPB单克隆抗体预孵育来防止该损伤。这些结果表明，CPB是CN 3685诱导的肠道病理学所必需的，也是足够的，支持该毒素在C型肠道发病机制中的关键作用。
Clostridium perfringens type C isolates, which cause enteritis necroticans in humans and enteritis and enterotoxaemias of domestic animals, typically produce (at minimum) beta toxin (CPB), alpha toxin (CPA) and perfringolysin O (PFO) during log-phase growth. To assist development of improved vaccines and therapeutics, we evaluated the contribution of these three toxins to the intestinal virulence of type C disease isolate CN3685. Similar to natural type C infection, log-phase vegetative cultures of wild-type CN3685 caused haemorrhagic necrotizing enteritis in rabbit ileal loops. When isogenic toxin null mutants were prepared using TargeTron (R) technology, even a double cpa/pfoA null mutant of CN3685 remained virulent in ileal loops. However, two independent cpb null mutants were completely attenuated for virulence in this animal model. Complementation of a cpb mutant restored its CPB production and intestinal virulence. Additionally, pre-incubation of wild-type CN3685 with a CPB-neutralizing monoclonal antibody rendered the strain avirulent for causing intestinal pathology. Finally, highly purified CPB reproduced the intestinal damage of wild-type CN3685 and that damage was prevented by pre-incubating purified CPB with a CPB monoclonal antibody. These results indicate that CPB is both required and sufficient for CN3685-induced enteric pathology, supporting a key role for this toxin in type C intestinal pathogenesis.