Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
BMC Microbiol. 2020 Apr 6;20(1):78. doi: 10.1186/s12866-020-01759-x.
To date, the microbiota of the human penis has been studied mostly in connection with circumcision, HIV risk and female partner bacterial vaginosis (BV). These studies have shown that male circumcision reduces penile anaerobic bacteria, that greater abundance of penile anaerobic bacteria is correlated with increased cytokine levels and greater risk of HIV infection, and that the penile microbiota is an important harbour for BV-associated bacteria. While circumcision has been shown to significantly reduce the risk of acquiring human papillomavirus (HPV) infection, the relationship of the penile microbiota with HPV is still unknown. In this study, we examined the penile microbiota of HPV-infected men as well as the impact of HIV status.
The penile skin microbiota of 238 men from Cape Town (South Africa) were profiled using Illumina sequencing of the V3-V4 hypervariable regions of the 16S rRNA gene. Corynebacterium and Prevotella were found to be the most abundant genera. Six distinct community state types (CSTs) were identified. CST-1, dominated by Corynebacterium, corresponded to less infections with high-risk HPV (HR-HPV) relative to CSTs 2-6. Men in CST-5 had greater relative abundances of Prevotella, Clostridiales, and Porphyromonas and a lower relative abundance of Corynebacterium. Moreover, they were significantly more likely to have HPV or HR-HPV infections than men in CST-1. Using a machine learning approach, we identified greater relative abundances of the anaerobic BV-associated bacteria (Prevotella, Peptinophilus, and Dialister) and lower relative abundance of Corynebacterium in HR-HPV-infected men compared to HR-HPV-uninfected men. No association was observed between HIV and CST, although the penile microbiota of HIV-infected men had greater relative abundances of Staphylococcus compared to HIV-uninfected men.
We found significant differences in the penile microbiota composition of men with and without HPV and HIV infections. HIV and HR-HPV infections were strongly associated with greater relative abundances of Staphylococcus and BV-associated bacterial taxa (notably Prevotella, Peptinophilus and Dialister), respectively. It is possible that these taxa could increase susceptibility to HIV and HR-HPV acquisition, in addition to creating conditions in which infections persist. Further longitudinal studies are required to establish causal relationships and to determine the extent of the effect.
迄今为止，人类阴茎的微生物群主要与割礼、HIV 风险和女性细菌性阴道病（BV）相关的研究有关。这些研究表明，男性割礼可减少阴茎厌氧细菌，阴茎厌氧细菌的丰度增加与细胞因子水平升高和 HIV 感染风险增加相关，阴茎微生物群是 BV 相关细菌的重要宿主。虽然割礼已被证明可显著降低人乳头瘤病毒（HPV）感染的风险，但阴茎微生物群与 HPV 的关系尚不清楚。在这项研究中，我们检查了 HPV 感染男性的阴茎微生物群以及 HIV 状态的影响。
对来自南非开普敦的 238 名男性的阴茎皮肤微生物群进行了研究，使用 Illumina 对 16S rRNA 基因的 V3-V4 高变区进行测序。发现棒状杆菌和普雷沃氏菌是最丰富的属。确定了六种不同的社区状态类型（CST）。以棒状杆菌为主的 CST-1 与高危 HPV（HR-HPV）感染相对较少有关，而 CST-2-6 则相反。CST-5 中的男性普雷沃氏菌、梭菌和卟啉单胞菌的相对丰度较高，棒状杆菌的相对丰度较低。此外，与 CST-1 中的男性相比，他们感染 HPV 或 HR-HPV 的可能性更大。使用机器学习方法，我们发现与 HR-HPV 未感染的男性相比，HR-HPV 感染的男性中厌氧性 BV 相关细菌（普雷沃氏菌、消化链球菌和戴阿利斯特菌）的相对丰度较高，而棒状杆菌的相对丰度较低。未观察到 HIV 与 CST 之间存在关联，尽管 HIV 感染男性的阴茎微生物群中葡萄球菌的相对丰度高于 HIV 未感染男性。
我们发现 HPV 和 HIV 感染男性与未感染男性的阴茎微生物群组成存在显著差异。HIV 和 HR-HPV 感染与葡萄球菌和 BV 相关细菌（特别是普雷沃氏菌、消化链球菌和戴阿利斯特菌）的相对丰度增加分别强烈相关。这些细菌可能会增加感染 HIV 和 HR-HPV 的易感性，并在感染持续的情况下创造条件。需要进一步的纵向研究来建立因果关系并确定其影响程度。
