An Emerging Mycoplasma Associated with Trichomoniasis, Vaginal Infection and Disease

Humans are colonized by thousands of bacterial species, but it is difficult to assess the metabolic and pathogenic potential of the majority of these because they have yet to be cultured. Here, we characterize an uncultivated vaginal mycoplasma tightly associated with trichomoniasis that was previously known by its 16S rRNA sequence as “Mnola.” In this study, the mycoplasma was found almost exclusively in women infected with the sexually transmitted pathogen Trichomonas vaginalis, but rarely observed in women with no diagnosed disease. The genomes of four strains of this species were reconstructed using metagenome sequencing and assembly of DNA from four discrete mid-vaginal samples, one of which was obtained from a pregnant woman with trichomoniasis who delivered prematurely. These bacteria harbor several putative virulence factors and display unique metabolic strategies. Genes encoding proteins with high similarity to potential virulence factors include two collagenases, a hemolysin, an O-sialoglycoprotein endopeptidase and a feoB-type ferrous iron transport system. We propose the name “Candidatus Mycoplasma girerdii” for this potential new pathogen.人类体内定殖着数千种细菌，但由于大多数细菌尚未实现体外培养，难以评估其代谢与致病潜力。本研究对一种与滴虫病紧密相关的未培养阴道支原体开展了系统表征，该支原体此前仅通过其16S核糖体RNA（16S rRNA）序列被称为“Mnola”。研究发现，该支原体几乎仅存在于感染性传播病原体阴道毛滴虫（Trichomonas vaginalis）的女性体内，而在未确诊疾病的女性中极少被检出。研究人员依托宏基因组测序与组装技术，从4份独立的阴道中段样本中重建了该物种的4株菌株基因组，其中1份样本来自一名患有滴虫病并早产的孕妇。这些细菌携带多种潜在毒力因子，并展现出独特的代谢策略。编码与潜在毒力因子高度相似蛋白的基因包括两种胶原酶、一种溶血素、一种O-唾液酸糖蛋白内切肽酶以及一套feoB型亚铁离子转运系统。我们提议将这一潜在新型病原体命名为候选支原体 girerdii（Candidatus Mycoplasma girerdii）。