Fate of the Urinary Tract Virus BK Human Polyomavirus in Source-Separated Urine
Fate of the Urinary Tract Virus BK Human Polyomavirus in Source-Separated Urine
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DOI：
10.1128/aem.02374-17
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发表时间：
2018-04-01
影响因子：
4.4
通讯作者：
Wigginton, Krista R.
中科院分区：
文献类型：
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作者：
Goetsch, Heather E.;Zhao, Linbo;Wigginton, Krista R.
人类多瘤病毒是一类新出现的病原体，感染着很大比例的人类群体，并通过尿液排出体外。因此，为生产肥料而收集的尿液中，多瘤病毒基因的浓度往往很高。我们通过感染性检测和定量聚合酶链反应（qPCR），研究了具有感染性的双链DNA（dsDNA）人类BK多瘤病毒（BKPyV）在经过水解的源分离尿液中的归宿。尽管BKPyV基因组在水解尿液中能长时间存在（T - 90[感染性或基因拷贝数减少90%所需的时间]大于3周），但在大多数测试尿液样本中，病毒很快就失去活性（T90为1.1至11小时）。有趣的是，双链DNA噬菌体替代物T3的感染性（T - 90为24至46天）比BKPyV持久得多，这凸显了使用噬菌体作为人类病毒替代物的一个重大缺陷。巴氏消毒和过滤实验表明，BKPyV病毒的失活是由于源分离尿液中的微生物活动，而SDS - PAGE蛋白质免疫印迹显示，BKPyV蛋白衣壳的解体与病毒失活同时发生。我们的研究结果表明，储存的尿液不会构成BKPyV传播的重大风险，qPCR和双链DNA替代物的感染性并不能准确描述BKPyV的归宿，并且微生物导致的失活是由BKPyV衣壳的结构元件驱动的。
重要意义：我们证明了一种常见的尿路病毒对水解尿液中的环境高度敏感，因此对于使用尿液衍生肥料的人类来说，不会构成重大的暴露途径。这些结果对于理解病毒的归宿具有重要意义。首先，我们的研究表明，尽管多瘤病毒的双链DNA基因组能持续数周，但感染性仅持续数小时至数天，这凸显了使用qPCR评估不可培养病毒风险的不足之处。其次，常用的双链DNA替代病毒在BK多瘤病毒仅能存活数小时的相同条件下能存活数周，这突出了使用病毒替代物预测人类病毒在环境中行为的问题。最后，我们的失活机制分析提供了有力证据，表明微生物活动可能通过衣壳解体驱动病毒快速失活。总体而言，我们的研究强调了病毒之间细微的结构差异如何极大地影响它们在环境中的归宿。
Human polyomaviruses are emerging pathogens that infect a large percentage of the human population and are excreted in urine. Consequently, urine that is collected for fertilizer production often has high concentrations of polyomavirus genes. We studied the fate of infectious double-stranded DNA (dsDNA) BK human polyomavirus (BKPyV) in hydrolyzed source-separated urine with infectivity assays and quantitative PCR (qPCR). Although BKPyV genomes persisted in the hydrolyzed urine for long periods of time (T-90 [time required for 90% reduction in infectivity or gene copies] of >3 weeks), the viruses were rapidly inactivated (T90 of 1.1 to 11 h) in most of the tested urine samples. Interestingly, the infectivity of dsDNA bacteriophage surrogate T3 (T-90 of 24 to 46 days) was much more persistent than that of BKPyV, highlighting a major shortcoming of using bacteriophages as human virus surrogates. Pasteurization and filtration experiments suggest that BKPyV virus inactivation was due to microorganism activity in the source-separated urine, and SDS-PAGE Western blots showed that BKPyV protein capsid disassembly is concurrent with inactivation. Our results imply that stored urine does not pose a substantial risk of BKPyV transmission, that qPCR and infectivity of the dsDNA surrogate do not accurately depict BKPyV fate, and that microbial inactivation is driven by structural elements of the BKPyV capsid.IMPORTANCE We demonstrate that a common urinary tract virus has a high susceptibility to the conditions in hydrolyzed urine and consequently would not be a substantial exposure route to humans using urine-derived fertilizers. The results have significant implications for understanding virus fate. First, by demonstrating that the dsDNA (double-stranded DNA) genome of the polyomavirus lasts for weeks despite infectivity lasting for hours to days, our work highlights the shortcomings of using qPCR to estimate risks from unculturable viruses. Second, commonly used dsDNA surrogate viruses survived for weeks under the same conditions that BK polyomavirus survived for only hours, highlighting issues with using virus surrogates to predict how human viruses will behave in the environment. Finally, our mechanistic inactivation analysis provides strong evidence that microbial activity drives rapid virus inactivation, likely through capsid disassembly. Overall, our work underlines how subtle structural differences between viruses can greatly impact their environmental fate.