Yoshida Sho, Inaba Hiroaki, Nomura Ryota, Murakami Masaru, Yasuda Hidemi, Nakano Kazuhiko, Matsumoto-Nakano Michiyo
Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
J Oral Microbiol. 2021 Apr 25;13(1):1914499. doi: 10.1080/20002297.2021.1914499.
: , a major periodontal pathogen in animals, possesses fimbriae that have been classified into three genotypes (A, B, C) based on the diversity of genes encoding fimbrillin protein (FimA). strains with type C fimbriae were previously shown to be more virulent than other types. In this study, we further examined the host toxicity mediated by fimbriae by constructing recombinant FimA (rFimA) expression vectors for each genotype and raised antibodies to the purified proteins. : All larvae died within 204 h following infection with type C at the low-dose infection, whereas type A and B did not. Among types, the survival rates of the larvae injected with rFimA type C were remarkably decreased, while the survival rates of the larvae injected with rFimA type A and type B were greater than 50%. Clindamycin treatment inhibited the growth of type C strains in a dose-dependent manner, resulting in an increased rate of silkworm survival. Finally, type C rFimA-specific antiserum prolonged the survival of silkworm larvae stimulated by infection with type C strain or injection of rFimA type C protein. : These results suggested that type C fimbriae have high potential for enhancement of bacterial pathogenesis, and that both clindamycin and anti-type C rFimA-specific antibodies are potent inhibitors of type C fimbriae-induced toxicity. This is the first report to establish a silkworm infection model using for toxicity assessment.
作为动物主要的牙周病原体，具有菌毛，根据编码菌毛蛋白（FimA）的基因多样性，这些菌毛已被分为三种基因型（A、B、C）。先前已表明具有C型菌毛的菌株比其他类型更具毒性。在本研究中，我们通过构建每种基因型的重组FimA（rFimA）表达载体并制备针对纯化蛋白的抗体，进一步研究了由菌毛介导的宿主毒性。：低剂量感染C型菌株后，所有幼虫在204小时内死亡，而A 型和B型则不然。在各类型中，注射C型rFimA的幼虫存活率显著降低，而注射A型和B型rFimA的幼虫存活率大于50%。克林霉素处理以剂量依赖方式抑制C型菌株的生长，导致家蚕存活率增加。最后，C型rFimA特异性抗血清延长了受C型菌株感染或注射C型rFimA蛋白刺激的家蚕幼虫的存活时间。：这些结果表明，C型菌毛具有增强细菌致病性的高潜力，并且克林霉素和抗C型rFimA特异性抗体都是C型菌毛诱导毒性的有效抑制剂。这是首次使用建立家蚕感染模型进行毒性评估的报告。
