Molecular characterization of Streptococcus mutans strains containing the cnm gene encoding a collagen-binding adhesin
Molecular characterization of Streptococcus mutans strains containing the cnm gene encoding a collagen-binding adhesin
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DOI：
10.1016/j.archoralbio.2009.11.008
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发表时间：
2010-01-01
影响因子：
3
通讯作者：
Ooshima, T.
中科院分区：
文献类型：
--
作者：
Nakano, K.;Nomura, R.;Ooshima, T.
目的：变形链球菌是龋病的主要致病菌，也是感染性心内膜炎的主要致病菌。其120-kDa Cnm蛋白与I型胶原结合，这可能是一个潜在的毒力因子。在这项研究中，我们描述了S。设计：共528株变形链球菌，用PCR方法检测其cnm基因编码区。研究了从日本、芬兰和泰国受试者分离的变异株。利用分子生物学技术，分析cnm阳性菌株的分布频率和插入cnm的位置。通过灭活cnm基因，构建等基因突变株，并对其胶原结合和葡聚糖结合的生物学特性进行评价。编码葡聚糖结合蛋白的基因的Southern杂交也performed.Results：从泰国科目的cnm阳性菌株的分布频率为12%，类似于以前报道的日本和芬兰科目。此外，所有cnm阳性临床分离株的cnm插入位置相同。至于从28株临床分离株构建的cnm失活突变株，其胶原结合活性可忽略不计。此外，在cnm阳性临床分离株中葡聚糖结合活性显著降低，并且对应于编码葡聚糖结合蛋白A的gbpA的缺乏。结论：我们的结果表明，具有cnm基因的菌株，是S.在几个不同的地理位置上以相似的频率可检测到变异株。此外，这些菌株的共同特性是高水平的胶原蛋白结合活性和低水平的葡聚糖结合活性的趋势。(C)2009爱思唯尔有限公司保留所有权利。
Objective: Streptococcus mutans, known to be a major pathogen of dental caries, is also considered to cause infective endocarditis. its 120-kDa Cnm protein binds to type I collagen, which may be a potential virulence factor. In this study, we characterized S. mutans clinical strains focusing on the cnm gene encoding Cnm.Design: A total of 528 S. mutans strains isolated from Japanese, Finnish, and Thai subjects were investigated. Using molecular techniques, the distribution frequency of cnm-positive strains and location of the inserted cnm were analyzed. Furthermore, isogenic mutant strains were constructed by inactivation of the cnm gene, then their biological properties of collagen-binding and glucan-binding were evaluated. Southern hybridization of the genes encoding glucan-binding proteins was also performed.Results: The distribution frequency of cnm-positive strains from Thai subjects was 12%, similar to that previously reported for Japanese and Finnish subjects. Furthermore, the location of insertion of cnm was the same in all cnm-positive clinical isolates. As for the cnm-inactivated mutant strains constructed from 28 clinical isolates, their collagen-binding activity was negligible. in addition, glucan-binding activity in the crim-positive clinical isolates was significantly reduced and corresponded to a lack of gbpA encoding glucan-binding protein A.Conclusions: Our results indicate that strains with cnm genes, the most crucial factor for the collagen-binding property of S. mutans, are detectable at similar frequencies over several different geographic locations. In addition, the common properties of these strains are a high level of collagen-binding activity and tendency for a low level of glucan-binding activity. (C) 2009 Elsevier Ltd. All rights reserved.