Institute of Biotechnology, Vilnius University, Vilnius, Lithuania.
National Public Health Surveillance Laboratory, Vilnius, Lithuania.
PLoS One. 2018 Jul 12;13(7):e0200625. doi: 10.1371/journal.pone.0200625. eCollection 2018.
The well-known genotypic and phenotypic diversity of G. vaginalis resulted in its classification into at least four subgroups (clades) with diverse genomic properties. To evaluate the virulence potential of G. vaginalis subgroups, we analyzed the virulence-related phenotypic characteristics of 14 isolates of clade 1, 12 isolates of clade 2, 8 isolates of clade 4 assessing their in vitro ability to grow as a biofilm, produce the toxin vaginolysin, and express sialidase activity. Significant differences in VLY production were found (p = 0.023), but further analysis of clade pairs did not confirm this finding. The amount of biofim did not differ significantly among the clades. Analysis of sialidase activity indicated statistically significant differences among the clades (p < 0.001). Production of active recombinant G. vaginalis sialidase demonstrated the link between the sld gene and enzymatic activity, which may be differentially regulated at the transcriptional level. Statistical classification analysis (random forests algorithm) showed that G. vaginalis clades could be best defined by the profiles of two phenotypic characteristics: sialidase activity and vaginolysin production. The results of principal component analysis and hierarchical clustering suggested that all isolates can be subgrouped into three clusters, the structures of which are determined based on phenotypic characteristics of the isolates. Clade 4 was the most homogenous group, as all isolates were found in the same cluster, which is characterized by low production of all studied virulence factors. Clade 2 isolates were mainly distributed between two clusters, whereas clade 1 isolates were found in all three clusters that were characterized by a distinct profile of phenotypic characteristics. Our findings suggest that G. vaginalis subgroups with different virulence potential might play distinct roles in vaginal microbiota.
阴道加德纳菌（G. vaginalis）具有众所周知的基因型和表型多样性，这导致其至少分为四个具有不同基因组特性的亚群（进化枝）。为了评估阴道加德纳菌亚群的毒力潜力，我们分析了 14 株 1 型进化枝、12 株 2 型进化枝和 8 株 4 型进化枝的 14 株分离株的与毒力相关的表型特征，评估它们在体外形成生物膜、产生毒素阴道溶素和表达唾液酸酶活性的能力。发现 VLY 产生量存在显著差异（p = 0.023），但进一步对进化枝对分析并未证实这一发现。各进化枝之间生物膜量无显著差异。唾液酸酶活性分析表明各进化枝之间存在统计学差异（p < 0.001）。活性重组阴道加德纳菌唾液酸酶的产生表明 sld 基因与酶活性之间存在关联，这可能在转录水平上受到差异调控。统计分类分析（随机森林算法）表明，阴道加德纳菌进化枝可通过两种表型特征的特征来最好地定义：唾液酸酶活性和阴道溶素产生。主成分分析和层次聚类的结果表明，所有分离株可根据分离株的表型特征分为三个亚群。结构由分离株的表型特征决定。4 型进化枝是最同质的群体，因为所有分离株都在相同的聚类中发现，其特征是所有研究的毒力因子的产量低。2 型进化枝的分离株主要分布在两个聚类之间，而 1 型进化枝的分离株存在于三个聚类中，其特征是表型特征的特征明显。我们的研究结果表明，具有不同毒力潜力的阴道加德纳菌亚群可能在阴道微生物群中发挥不同的作用。
