Bulavaitė Aistė, Dapkūnas Justas, Reškevičiūtė Raminta, Dalgėdienė Indrė, Valančauskas Lukas, Baranauskienė Lina, Plečkaitytė Milda
Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
Front Cell Infect Microbiol. 2025 May 8;15:1556232. doi: 10.3389/fcimb.2025.1556232. eCollection 2025.
Bacterial vaginosis (BV), a form of vaginal dysbiosis, is associated with numerous adverse reproductive and obstetric outcomes. spp. are among the key bacteria identified in most BV cases. The formation of a polymicrobial -dominated biofilm on the vaginal epithelium is a characteristic diagnostic marker of BV. colonization and biofilm formation indicate a significant adhesion potential, the determinants of which remain unexplored. In this initial approach to identify adhesins, we analyzed the Cna protein located on the ATCC 14018 cell surface as determined previously. Structure modeling of Cna (designated Grd Cna) revealed that the protein contains N2 and N3 domains with an immunoglobulin (IgG)-like fold, which shows structural homology to the corresponding domains in SdrD and UafA proteins of the microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) family. A single B domain shares structural similarity with the corresponding domain of Sdr proteins. The R region is rich in PKD repeats, while the C-terminal contains a non-canonical LVNTG cell wall sorting motif. The gene was predominantly detected in isolates but was absent in other commonly identified species isolates. The recombinant Grd Cna protein binds dose-dependently to human fibrinogen but does not interact with fibronectin or collagen types I, III, or IV. Cna-positive cells adhered to immobilized fibrinogen; however, recombinant Cna did not inhibit this binding, suggesting that Cna may not be a major adhesin mediating adherence to this ECM component.
细菌性阴道病（BV）是一种阴道生态失调形式，与众多不良生殖和产科结局相关。在大多数BV病例中，已确定某些菌种是关键细菌。阴道上皮上形成以多种微生物为主的生物膜是BV的一个特征性诊断标志物。该菌种的定植和生物膜形成表明其具有显著的黏附潜力，但其决定因素仍未得到探索。在这种鉴定黏附素的初步方法中，我们分析了先前确定的位于ATCC 14018细胞表面的Cna蛋白。Cna（命名为Grd Cna）的结构建模显示，该蛋白包含具有免疫球蛋白（IgG）样折叠的N2和N3结构域，与识别黏附基质分子的微生物表面成分（MSCRAMMs）家族的SdrD和UafA蛋白中的相应结构域具有结构同源性。单个B结构域与Sdr蛋白的相应结构域具有结构相似性。R区域富含PKD重复序列，而C末端包含一个非典型的LVNTG细胞壁分选基序。该基因主要在某些分离株中检测到，但在其他常见鉴定的菌种分离株中不存在。重组Grd Cna蛋白与人类纤维蛋白原呈剂量依赖性结合，但不与纤连蛋白或I、III或IV型胶原蛋白相互作用。Cna阳性细胞黏附于固定化的纤维蛋白原；然而，重组Cna并不抑制这种结合，这表明Cna可能不是介导该菌种黏附于这种细胞外基质成分的主要黏附素。
