Picobirnaviruses: prevalence, genetic diversity, detection methods

Abstract

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 metagenomics analysis is highlighted, and so is the possibility of using PBV as a marker for environmental monitoring.

Understanding the Genetic Diversity of Picobirnavirus: A Classification Update Based on Phylogenetic and Pairwise Sequence Comparison Approaches

“…), invertebrates (mollusks, insects, etc. ), and in environmental samples like sewage [ 8 ]. Identical sequences found in different hosts (e.g., pigs and humans) gives an indication of its facile spread, the absence of species barriers, and the lack of virus–host coevolutionary relationships [ 4 , 6 ].…”

“…Cited as evidence is the inability to culture in mammalian cells, the presence of 5′ Shine–Dalgarno sequences, its relatedness to fungus-infecting partitiviruses, and the usage of an alternate, mitochondrial genetic code by some PBVs [ 10 ]. Regardless of what kingdom they truly infect, PBVs exhibit a high degree of genetic diversity [ 8 ].…”

Virome in healthy pangolins reveals compatibility with multiple potentially zoonotic viruses

“…Picobirnavirus is routinely detected in stool samples ( Navarro et al, 2017 ); however, there is growing evidence that it is also present in the upper respiratory tract ( Berg et al, 2021 ; Huaman et al, 2021 ). Picobirnavirus species are considered opportunistic due to their association with diarrhea in humans and animals; however, their epidemiology and pathogenicity have not yet been characterized ( Kashnikov et al, 2020 ). Therefore, this rapidly evolving and easily transmitted virus requires continued attention to prevent the emergence of disease-causing variants.…”

Differences in selective profiles among single or double stranded DNA or RNA viruses. Statistical detection of its double or single stranded condition

“…A plausible explanation is the fact that this virus replicates by using a negative DNA strand after constructing a dsDNA (6, 7). The Marmot Picobirnaviridae a dsRNA virus (8) shows a non-significant larger selective profile difference between I-Par than I-a-Par, this is perhaps it is a very small virus (4.579 bp). However, Gentian Kobu sho-associated virus also a dsRNA virus (9) according to the Oxford database shows a big significant difference as expected; however, other authors present it as an ssRNA virus (10).…”