Development of infection mechanism of culture-negative endocarditis

粘连肉芽杆菌是口腔微生物群的一员，以前被称为营养变异链球菌，通常从心内膜炎患者中分离出来。在本研究中，我们以cshA序列为探针，通过斑块杂交程序鉴定了一种与纤维连接蛋白结合的表面蛋白Cha，该蛋白编码戈多氏链球菌DL1的纤维连接蛋白结合分子。cha序列与cshA高度同源，编码2351个氨基酸残基的产物。该蛋白在n端半区包含一个独特的序列。c端包含9个完整和1个不完整的115个氨基酸残基重复区。在8株营养变异链球菌中，3株adiacens链球菌和1株无营养缺陷链球菌携带cha基因。

Granulicatella adiacens is a member of the oral microbiota, formerly known as nutritionally variant streptococci, and is often isolated from endocarditis patients. In the present study we identified a surface protein, designated Cha, which binds to fibronectin, by a plaque hybridization procedure using the cshA sequence as probe, which encodes a fibronectin-binding molecule of Streptococcus gordonii DL1. The cha sequence was highly homologous to cshA and encoded a product of 2351 amino acid residues. The protein comprised a unique sequence in the N-terminal half region. The C-terminal region contained nine complete, and one incomplete, 115-amino acid residue repeat blocks. Among eight strains of nutritionally variant streptococci, three G. adiacens strains and one Abiotrophia defectiva strain carried the cha gene.