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This study aimed to detect picobirnavirus (PBV) in the fecal samples of wild and domestic animals from 2014 to 2016 in the Amazon biome. Fecal samples from different animals, including birds (n = 41) and mammals (n = 217), were used. The PAGE test showed negativity for PBV. However, 32 samples (12.4%, 32/258) showed positive results in RT-PCR analyses. Among the positive samples, pigs and cats, both with 28.12% (9/32), registered the highest frequencies. In a phylogenetic analysis, eight sequences from positive samples were grouped in the Genogroup 1 of PBV (PBV GI). PBV occurrence was significantly related to cats and pigs but not other mammals or birds, independently of their geographical origin. A nucleotide analysis demonstrated similarity among the feline group but the absence of a defined structure between the clades. PBVs are highly widespread viruses that can affect the most diverse types of hosts in the Amazon biome, including humans.

Picobirnaviruses (PBV) are found in a wide range of hosts and typically associated with gastrointestinal infections in immunocompromised individuals. Here, a divergent PBV genome was assembled from a patient hospitalized for acute respiratory illness (ARI) in Colombia. The RdRp protein branched with sequences previously reported in patients with ARI from Cambodia and China. Sputa from hospitalized individuals (n = 130) were screened by RT-qPCR which enabled detection and subsequent metagenomic characterization of 25 additional PBV infections circulating in Colombia and the US. Phylogenetic analysis of RdRp highlighted the emergence of two dominant lineages linked to the index case and Asian strains, which together clustered as a distinct genotype. Bayesian inference further established capsid and RdRp sequences as both significantly associated with ARI. Various respiratory-tropic pathogens were detected in PBV+ patients, yet no specific bacteria was common among them and four individuals lacked co-infections, suggesting PBV may not be a prokaryotic virus nor exclusively opportunistic, respectively. Competing models for the origin and transmission of this PBV genotype are presented that attempt to reconcile vectoring by a bacterial host with human pathogenicity. A high prevalence in patients with ARI, an ability to reassort, and demonstrated global spread indicate PBV warrant greater public health concern.

Picobirnaviruses (PBVs) are small, double stranded RNA viruses with an ability to infect a myriad of hosts and possessing a high degree of genetic diversity. PBVs are currently classified into two genogroups based upon classification of a 200 nt sequence of RdRp. We demonstrate here that this phylogenetic marker is saturated, affected by homoplasy, and has high phylogenetic noise, resulting in 34% unsolved topologies. By contrast, full-length RdRp sequences provide reliable topologies that allow ancestralism of members to be correctly inferred. MAFFT alignment and maximum likelihood trees were established as the optimal methods to determine phylogenetic relationships, providing complete resolution of PBV RdRp and capsid taxa, each into three monophyletic groupings. Pairwise distance calculations revealed these lineages represent three species. For RdRp, the application of cutoffs determined by theoretical taxonomic distributions indicates that there are five genotypes in species 1, eight genotypes in species 2, and three genotypes in species 3. Capsids were also divided into three species, but sequences did not segregate into statistically supported subdivisions, indicating that diversity is lower than RdRp. We thus propose the adoption of a new nomenclature to indicate the species of each segment (e.g., PBV-C1R2).

Picobirnaviruses (PBVs) have been detected in several species of animals worldwide; however, data pertaining to their presence in Australian wild and domestic animals are limited. Although PBVs are mostly found in faecal samples, their detection in blood and respiratory tract samples raises questions concerning their tropism and pathogenicity. We report here PBV detection in wild deer and cattle from southeastern Australia. Through metagenomics, the presence of PBV genogroups I (GI) and II (GII) were detected in deer serum and plasma. Molecular epidemiology studies targeting the partial RNA-dependent RNA polymerase gene were performed in a wide range of specimens (serum, faeces, spleen, lung, nasal swabs, and trachea) collected from wild deer and cattle, with PCR amplification obtained in all specimen types except lung and spleen. Our results reveal the predominance of GI and concomitant detection of both genogroups in wild deer and cattle. In concordance with other studies, the detected GI sequences displayed high genetic diversity, however in contrast, GII sequences clustered into three distinct clades. Detection of both genogroups in the upper respiratory tract (trachea and nasal swab) of deer in the present study gives more evidence about the respiratory tract tropism of PBV. Although much remains unknown about the epidemiology and tropism of PBVs, our study suggests a wide distribution of these viruses in southeastern Australia.

Sewage-associated viruses can cause several human and animal diseases, such as gastroenteritis, hepatitis, and respiratory infections. Therefore, their detection in wastewater can reflect current infections within the source population. To date, no viral study has been performed using the sewage of any large South American city. In this study, we used viral metagenomics to obtain a single sample snapshot of the RNA virosphere in the wastewater from Santiago de Chile, the seventh largest city in the Americas. Despite the overrepresentation of dsRNA viruses, our results show that Santiago’s sewage RNA virosphere was composed mostly of unknown sequences (88%), while known viral sequences were dominated by viruses that infect bacteria (60%), invertebrates (37%) and humans (2.4%). Interestingly, we discovered three novel genogroups within the Picobirnaviridae family that can fill major gaps in this taxa’s evolutionary history. We also demonstrated the dominance of emerging Rotavirus genotypes, such as G8 and G6, that have displaced other classical genotypes, which is consistent with recent clinical reports. This study supports the usefulness of sewage viral metagenomics for public health surveillance. Moreover, it demonstrates the need to monitor the viral component during the wastewater treatment and recycling process, where this virome can constitute a reservoir of human pathogens.

Picobirnaviruses (PBVs), family Picobirnaviridae, are bi-segmented, double-stranded RNA viruses. PBVs are considered opportunistic enteric pathogens. Gene segment-1 of PBV encodes the capsid protein, whilst gene segment-2 codes for RNA-dependent RNA polymerase (RdRp). Based on differences in gene segment-2, PBVs are classified into genogroup-I (GI) and GII. Although PBVs have been detected in a wide variety of host species, there are no reports on PBVs from mongoose so far. We report here high rates of detection (35.36%, 29/82) of GI PBVs in fecal samples from the small Indian mongoose (Herpestes auropunctatus) on the Caribbean island of St. Kitts. Applying a combination of a non-specific primer-based amplification method and conventional RT-PCR using a newly designed primer targeting the 3′-untranslated region (UTR), we could amplify and sequence the complete/nearly complete gene segment-2 of eight mongoose PBV strains. Except for a single strain, the gene segment-2 of the remaining mongoose PBV strains contained the putative open reading frame encoding the RdRp. The gene segment-2/putative RdRps of the mongoose PBV strains retained various features that are conserved in other PBVs (5′- and 3′-terminal nucleotide sequences, bacterial ribosomal binding site sequence in 5′-UTR, and the three domains in putative RdRps). On the other hand, phylogenetic analysis and sequence identities of the putative RdRps revealed high genetic diversity among the mongoose PBV strains and with those of PBVs from other host species. To our knowledge, this is the first report on detection and genetic diversity of PBVs from the mongoose, expanding the host range of PBVs and providing vital insights into the various features and evolution of putative RdRps of PBVs in a new host species.

We report high rates of detection (35.36%, 29/82) of genogroup-I (GI) picobirnaviruses (PBVs) in non-diarrheic fecal samples from the small Indian mongoose (Urva auropunctata). In addition, we identified a novel PBV-like RNA-dependent RNA polymerase (RdRp) gene sequence that uses an alternative mitochondrial genetic code (that of mold or invertebrate) for translation. The complete/nearly complete gene segment-2/RdRp gene sequences of seven mongoose PBV GI strains and the novel PBV-like strain were obtained by combining a modified non-specific primer-based amplification method with conventional RT-PCRs, facilitated by the inclusion of a new primer targeting the 3′-untranslated region (UTR) of PBV gene segment-2. The mongoose PBV and PBV-like strains retained the various features that are conserved in gene segment-2/RdRps of other PBVs. However, high genetic diversity was observed among the mongoose PBVs within and between host species. This is the first report on detection of PBVs in the mongoose. Molecular characterization of the PBV and PBV-like strains from a new animal species provided important insights into the various features and complex diversity of PBV gene segment-2/putative RdRps. The presence of the prokaryotic ribosomal binding site in the mongoose PBV genomes, and analysis of the novel PBV-like RdRp gene sequence that uses an alternative mitochondrial genetic code (especially that of mold) for translation corroborated recent speculations that PBVs may actually infect prokaryotic or fungal host cells.