Kashnikov A Yu, Epifanova N V, Novikova N A
I.N. Blokhina Nizhny Novgorod Research Institute of Epidemiology and Microbiology, Nizhny Novgorod, Russia.
Vavilovskii Zhurnal Genet Selektsii. 2020 Oct;24(6):661-672. doi: 10.18699/VJ20.660.
This article presents a general overview of the prevalence, genetic diversity and detection methods of picobirnaviruses (PBVs), which are small, non-enveloped icosahedral viruses with a segmented double-stranded RNA genome consisting of two segments taxonomically related to the genus Picobirnavirus of the family Picobirnaviridae. This review of scientific papers published in 1988-2019 provides data on the PBV distribution in the nature and a broad host range. PBV infection is characterized as opportunistic, the lack of understanding of the etiological role of PBVs in diarrhea is emphasized, since these viruses are detected both in symptomatic and asymptomatic cases. The concept of PBV infection as a chronic disease caused by a long-lasting persistence of the virus in the host is considered. Such factors as stress syndrome, physiological conditions, immune status and host age at the time of primary PBV infection influence the virus detection rate in humans and animals. The possible zoonotic nature of human PBV infection is noted due to the capacity for interspecies PBV transmission acquired during evolution as a result of the reassortment of the genome segments of different viruses infecting the same host. Data providing evidence that PBVs belong to eukaryotes and a challenging hypothesis stating that PBVs are bacterial viruses are presented. The need to intensify work on PBV detection because of their wide distribution, despite the complexity due to the lack of the cultivation system, is emphasized. Two strategies of RT-PCR as main PBV detection methods are considered. The genomes of individual representatives of the genus isolated from different hosts are characterized. Emphasis is placed on the feasibility of developing primers with broader specificity for expanding the range of identifiable representatives of the genus PBV due to a huge variety of their genotypes. The importance of effective monitoring of PBV prevalence for studying the zoonotic and anthroponotic potential using metagenomic analysis is highlighted, and so is the possibility of using PBV as a marker for environmental monitoring.
本文概述了微小双股RNA病毒（PBV）的流行情况、遗传多样性及检测方法。PBV是一种小型、无包膜的二十面体病毒，其基因组为分段双链RNA，由两个片段组成，在分类学上与双股RNA病毒科微小双股RNA病毒属相关。这篇对1988年至2019年发表的科学论文的综述提供了PBV在自然界中的分布数据以及广泛的宿主范围。PBV感染具有机会性特征，强调了对PBV在腹泻中病因作用的认识不足，因为这些病毒在有症状和无症状病例中均有检测到。考虑了PBV感染作为一种由病毒在宿主体内长期持续存在引起的慢性疾病的概念。诸如应激综合征、生理状况、免疫状态以及初次感染PBV时的宿主年龄等因素会影响人和动物体内病毒的检测率。由于在进化过程中不同病毒感染同一宿主时基因组片段的重配，使得PBV具有种间传播能力，因此指出了人类PBV感染可能具有人畜共患病的性质。文中呈现了支持PBV属于真核生物的数据以及一个具有挑战性的假说，即PBV是细菌病毒。强调了尽管由于缺乏培养系统而导致复杂性，但由于PBV分布广泛，仍需加强其检测工作。文中考虑了作为主要PBV检测方法的两种RT-PCR策略。对从不同宿主分离出的该属个别代表的基因组进行了表征。由于PBV基因型种类繁多，重点强调了开发具有更广泛特异性的引物以扩大可识别的PBV属代表范围的可行性。强调了使用宏基因组分析有效监测PBV流行情况对于研究人畜共患病和人传人的潜力的重要性，以及将PBV用作环境监测标志物的可能性。
