Szczesny Adam, Martirosian Gayane, Cohen Stuart, Silva Joseph
Department of Medical Microbiology Medical University of Silesia, Katowice, Poland.
Pol J Microbiol. 2005;54(4):301-4.
Male Syrian hamsters (Mesocricetus auratus) were used to study interactions between different toxin deficient strains of C. difficile. After sensitization with clindamycin, hamsters were intragastrically co-infected with the appropriate dilutions corresponding to 100, 1000 and 10,000 cells of four (toxin A or B-deficient) C. difficile strains (8864, P-829, W-38 and W-74). In addition, a group of hamsters was infected with C. difficile VPI 10463, a reference toxigenic strain. Colonization and mortality was observed within 48 hours in the group of hamsters infected with the reference toxigenic strain. No clinical disease was observed in the groups of hamsters co-infected with the toxin A or B-deficient strains. Re-infection of these hamsters (co-infected with toxin deficient isolates) with C. difficile VPI 10463 resulted in clinical disease and death suggesting that these strains do not confer protection against infection with a toxigenic strain. Macroscopic and microscopic observations of the cecum of re-infected hamsters demonstrated uniformly multiple large hemorrhagic areas without pseudomembranes. Hamsters infected with as few as 100-500 cells of the toxigenic strain--VPI 10463 alone demonstrated pseudomembranes and multiple hemorrhages. These results suggest that even though the toxin deficient strains did not prevent re-infection with a toxigenic strain of C. difficile, they may play a role in the histopathologic changes after re-infections in the hamster model. Further studies with a larger number of hamsters and C. difficile strains of various molecular profiles are required to better understand the interaction between these strains.
雄性叙利亚仓鼠（金黄仓鼠）被用于研究艰难梭菌不同毒素缺陷菌株之间的相互作用。在用克林霉素致敏后，仓鼠经胃内共同感染四种（毒素A或B缺陷型）艰难梭菌菌株（8864、P - 829、W - 38和W - 74）分别对应100、1000和10000个细胞的适当稀释液。此外，一组仓鼠感染了艰难梭菌VPI 10463，一种参考产毒菌株。在感染参考产毒菌株的仓鼠组中，48小时内观察到了定植和死亡率。在共同感染毒素A或B缺陷菌株的仓鼠组中未观察到临床疾病。用艰难梭菌VPI 10463对这些仓鼠（共同感染毒素缺陷型分离株）进行再次感染导致了临床疾病和死亡，这表明这些菌株不能提供针对产毒菌株感染的保护。对再次感染仓鼠的盲肠进行宏观和微观观察发现，均匀分布着多个大的出血区域，没有假膜。仅感染低至100 - 500个产毒菌株——VPI 10463细胞的仓鼠出现了假膜和多处出血。这些结果表明，尽管毒素缺陷菌株不能预防艰难梭菌产毒菌株的再次感染，但它们可能在仓鼠模型再次感染后的组织病理学变化中起作用。需要用更多数量的仓鼠和具有各种分子谱的艰难梭菌菌株进行进一步研究，以更好地理解这些菌株之间的相互作用。
