Borriello S P, Barclay F E
J Med Microbiol. 1985 Jun;19(3):339-50. doi: 10.1099/00222615-19-3-339.
Prior colonisation of clindamycin-treated hamsters with non-toxigenic strains of C. difficile protected them from subsequent colonisation with a toxigenic pathogenic strain. In total, 13 of 18 'protected' hamsters survived for up to 27 days whereas all 27 animals challenged with the toxigenic strain alone died within 48 h. Protection was not evident if a heat-killed suspension was used or if the colonising non-toxigenic strain was first removed with vancomycin. No antitoxic activity could be detected in the faeces of animals colonised with the non-toxigenic strains. Other species of clostridia did not protect against the lethal effects of subsequent exposure to the toxigenic strain. Conversely, non-toxigenic strains would not protect the animals from the lethal effects of a different clostridial pathogen, C. spiroforme. In most cases, even in the protected animals, the toxigenic strain eventually became dominant and caused disease, with translocation across the gut wall occurring early in the disease process. It was also shown that a non-toxigenic strain of C. difficile can adhere to gut mucosa. It is proposed that the protection afforded by the non-toxigenic strains may be due to competition for ecological niches.
用艰难梭菌非产毒株预先定殖经克林霉素治疗的仓鼠，可保护它们免受随后产毒致病菌株的定殖。总共18只“受保护”的仓鼠中有13只存活了长达27天，而单独用产毒菌株攻击的所有27只动物在48小时内死亡。如果使用热灭活悬液，或者先用万古霉素清除定殖的非产毒株，则没有明显的保护作用。在定殖有非产毒株的动物粪便中未检测到抗毒素活性。其他梭菌属物种不能保护动物免受随后接触产毒菌株的致死作用。相反，非产毒株不能保护动物免受另一种梭菌病原体——螺旋形梭菌的致死作用。在大多数情况下，即使在受保护的动物中，产毒菌株最终也会占主导并引发疾病，在疾病过程早期就会发生跨肠壁的移位。研究还表明，艰难梭菌的非产毒株可以粘附于肠道黏膜。有人提出，非产毒株提供的保护可能是由于对生态位的竞争。
