Gardnerella spp. are pathognomonic for bacterial vaginosis, which increases the risk of preterm birth and the transmission of sexually transmitted infections. Gardnerella spp. are genetically diverse, comprising what have recently been defined as distinct species with differing functional capacities. Disease associations with Gardnerella spp. are not straightforward: patients with BV are usually infected with multiple species, and Gardnerella spp. are also found in the vaginal microbiome of healthy women. Genome comparisons of Gardnerella spp. show evidence of lateral gene transfer (LGT), but patterns of LGT have not been characterized in detail. Here we sought to define the role of LGT in shaping the genetic structure of Gardnerella spp. We analyzed whole genome sequencing data for 106 Gardnerella strains and used these data for pan genome analysis and to characterize LGT in the core and accessory genomes, over recent and remote timescales. In our diverse sample of Gardnerella strains, we found that both the core and accessory genomes are clearly differentiated in accordance with newly defined species designations. We identified putative competence and pilus assembly genes across most species; we also found them to be differentiated between species. Competence machinery has diverged in parallel with the core genome, with selection against deleterious mutations as a predominant influence on their evolution. By contrast, the virulence factor vaginolysin, which encodes a toxin, appears to be readily exchanged among species. We identified five distinct prophage clusters in Gardnerella genomes, two of which appear to be exchanged between Gardnerella species. Differences among species are apparent in their patterns of LGT, including their exchange with diverse gene pools. Despite frequent LGT and co-localization in the same niche, our results show that Gardnerella spp. are clearly genetically differentiated and yet capable of exchanging specific genetic material. This likely reflects complex interactions within bacterial communities associated with the vaginal microbiome. Our results provide insight into how such interactions evolve and are maintained, allowing these multi-species communities to colonize and invade human tissues and adapt to antibiotics and other stressors.

加德纳菌属spp。是细菌性阴道病的病原体，可增加早产和性传播感染的传播风险。加德纳菌属spp。具有遗传多样性，包括最近被定义为具有不同功能能力的不同物种。疾病关联加德纳菌属spp。并非一帆风顺：BV患者通常感染多种菌种，并且加德纳菌属spp。在健康女性的阴道微生物组中也有发现。的基因组比较加德纳菌属spp。虽然显示出侧向基因转移（LGT）的证据，但LGT的模式尚未详细描述。在这里，我们试图定义LGT在塑造棉铃虫的遗传结构中的作用。加德纳菌属spp。我们分析了106个全基因组测序数据加德纳菌属菌株，并将这些数据用于全基因组分析，并在近期和远程时间尺度上表征核心和辅助基因组中的LGT。在我们多样化的样本中加德纳菌属菌株，我们发现根据新定义的物种名称，核心基因组和辅助基因组均明显不同。我们确定了大多数物种的推定能力和菌毛组装基因。我们还发现它们在物种之间有所区别。竞争机制已与核心基因组并行发展，针对有害突变的选择是对其进化的主要影响。相比之下，编码毒素的毒力因子vaginolysin似乎很容易在物种之间交换。我们确定了五个不同的预言集群加德纳菌属 基因组，其中两个似乎在 加德纳菌属种类。物种之间的LGT模式差异很明显，包括它们与不同基因库的交换。尽管在同一个细分市场中经常发生LGT和共同定位，但我们的结果表明加德纳菌属spp。具有明显的遗传分化能力，但仍能够交换特定的遗传物质。这可能反映了与阴道微生物组相关的细菌群落内部的复杂相互作用。我们的结果提供了对这种相互作用如何发展和维持的见解，从而使这些多物种群落能够定殖和侵入人体组织并适应抗生素和其他应激源。