Circulation of picobirnavirus in Neotropical free-ranging mammals.

Picobirnavirus (PBV) is a family of non-enveloped double-stranded RNA viruses with bisegmented genomes. Segment 1 encodes the capsid protein and segment 2 encodes RNA-dependent RNA polymerase. They exhibit high genomic heterogeneity and infect a wide range of vertebrate hosts, including humans. The objective of this study was to expand our knowledge of the circulation of PBV in free-living animals from two regions (Brazil and Argentina) of the Atlantic Forest. Fecal samples were analyzed from free-living animals: tapir, brocket deer, peccary, and different species of rodents and marsupials. A total of 133 samples were collected and analyzed by RT-PCR, of which 44 (33.08%) were PBV-positive. Nine amplicons were sequenced, five species from Argentina and four from Brazil, and phylogenetic analysis was performed. The nucleotide and amino acid identities of the PBV strains detected in animals from Argentina and Brazil were between 66.3% and 82.5% and between 55.3% and 74.2%, respectively. The analysed strains presented conserved nucleotide blocks without distinction of the host species. The phylogenetic tree showed that PBV strains from Atlantic Forest animals belonging to genogroup I were grouped into different clusters, without defining groups according to host species (human or animal) or the geographical area of detection. This is the first study on PBV in free-living animals in the Atlantic Forest. Our analysis suggested that PBV strains can infect different animal species, leading to PBV transmission between animals and humans. This reinforces the hypothesis of previous crossover points in the ecology and evolution of heterologous PBV strains.

Proposal of a pathway for enteric virus groups detection as indicators of faecal contamination to enhance the evaluation of microbiological quality in freshwater in Argentina.

An environmental survey was conducted in order to assess the frequency of detection of picobirnavirus (PBV), human adenovirus (HAdV) and infective enterovirus (iEV) as indicators of faecal contamination in freshwater, and to determine their potential as reporters of the presence of other enteric viruses, such as group A rotavirus (RVA). The study was carried out over a three-year period (2013-2015) in the San Roque Dam, Córdoba, Argentina. The overall frequency detection was 62.9% for PBV, 64.2% for HAdV and 70.4% for iEV. No significant differences were observed in the rates of detection for any of these viruses through the years studied, and a seasonal pattern was not present. Whenever there was RVA detection in the samples analyzed, there was also detection of iEV and/or HAdV and/or PBV. At least one of the viral groups analyzed was demonstrated in the 100% of the samples with faecal coliforms values within the guideline limits. In this setting, especially in those samples which reveal faecal indicator bacteria within the guideline limit, we propose to carry out a pathway, involving PBV, HAdV and iEV detection in order to enhance the evaluation of microbiological quality in freshwater in Argentina. The proposed methodological strategy could report faecal contamination in water, mainly of human origin, and the condition of the matrix to maintain viral viability. In addition, the viral groups selected could report the presence of RV.

Detection and partial molecular characterization of Picobirnavirus in swine from the state of Minas Gerais, Brazil.

Picobirnavirus (PBV) is a small two-segmented double-stranded RNA (dsRNA) virus that has been identified in diarrheic feces of a large range of animal hosts, including humans. For this reason, PBV has been recognized as an opportunistic agent of gastrointestinal disease. Even under these circumstances, there is a lack of studies regarding this pathogen. Not outstanding, in Brazil, the single description of the PBV occurrence in pigs was provided in the 1980s. Hence, this study aimed to verify the PBV occurrence in Brazilian swine farms and to perform molecular characterization of the identified strains. High genetic variability was found in the analyzed sequences. Further studies comprehending the infection of swine by PBV in Brazilian herds should be performed to provide more accurate information on its epidemiology and to discuss the role of the virus in gastrointestinal diseases.

Metagenomic Insights into the Sewage RNA Virosphere of a Large City.

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.

High detection rates and genetic diversity of picobirnaviruses (PBVs) in pigs on St. Kitts Island: Identification of a porcine PBV strain closely related to simian and human PBVs.

We report here high rates (75.38%, 49/65) of detection of genogroup I (GI) PBVs in diarrheic pigs on the Caribbean island of St. Kitts. High quality gene segment-2 sequences encoding a significant region (~350 amino acid (aa) residues) of the putative RNA-dependent RNA polymerase (RdRp) were obtained for 23 PBV strains. The porcine PBV strains from St. Kitts exhibited high genetic diversity among themselves (deduced aa identities of 56-100%) and with other PBVs (maximum deduced aa identities of 64-97%), and retained the three domains that are conserved in putative RdRps of PBVs. The nearly complete gene segment-2 sequence (full-length minus partial 3'- untranslated region) of a porcine PBV strain (strain PO36 from St. Kitts) that is closely related (deduced aa identities of 96-97%) to simian and human GI PBVs was determined using a combination of the non-specific primer-based amplification method and conventional RT-PCR. The complete putative RdRp sequence of strain PO36 preserved the various features that are maintained in PBVs from various species. For the first time, several co-circulating PBV strains from pigs were characterized for a significant region (~350 aa) of the putative RdRp, providing important insights into the genetic diversity of PBVs in a porcine population. Taken together, these observations corroborated growing evidence that PBVs can be highly prevalent and show limited correlation globally with host species or geography. This is the first report on detection of PBVs in pigs from the Caribbean region.

Detection and Molecular Characterization of Picobirnaviruses (PBVs) in the Mongoose: Identification of a Novel PBV Using an Alternative Genetic Code.

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.

The True Host/s of Picobirnaviruses.

Picobirnaviruses (PBVs) are bisegmented double-stranded RNA viruses that have been detected in a wide variety of animal species including invertebrates and in environmental samples. Since PBVs are ubiquitous in feces/gut contents of humans and other animals with or without diarrhea, they were considered as opportunistic enteric pathogens of mammals and avian species. However, the virus remains to be propagated in animal cell cultures, or in gnotobiotic animals. Recently, the classically defined prokaryotic motif, the ribosomal binding site sequence, has been identified upstream of putative open reading frame/s in PBV and PBV-like sequences from humans, various animals, and environmental samples, suggesting that PBVs might be prokaryotic viruses. On the other hand, based on the detection of some novel PBV-like RNA-dependent RNA polymerase sequences that use the alternative mitochondrial genetic code (that of mold or invertebrates) for translation, and principal component analysis of codon usage bias for these sequences, it has been proposed that PBVs might be fungal viruses with a lifestyle reminiscent of mitoviruses. These contradicting observations warrant further studies to ascertain the true host/s of PBVs, which still remains controversial. In this minireview, we have focused on the various findings that have raised a debate on the true host/s of PBVs.

Genetic diversity of bovine Picobirnavirus, Brazil.

Picobirnaviruses (PBVs) are emerging and opportunistic viruses with possible zoonotic potential. In this study, we present the detection, molecular characterization, and genotypic differentiation of PBVs from genogroup I in bovine stool samples from different Brazilian regions. A high proportion of PCR-positive samples (23.4%) was detected in a total of 77 analyzed. Nucleotide identity, alignment, and phylogenetic analyses revealed high diversity among the studied sequences. The results obtained indicate, for the first time, the circulation of bovine PBVs belonging to genogroup I in different Brazilian states, with heterogeneous phylogenetic-clustering profiles.

High detection rate and genetic diversity of picobirnavirus in a sheep flock in Brazil.

This study reports the detection by RT-PCR and molecular characterization of partial RdRp gene of picobirnavirus (PBV) dsRNA in fecal samples (n = 100) from a meat sheep flock in southern Brazil. The analysis of the results allowed the identification of two important characteristics of PBV infection. The first was the high frequency of infection in the sheep flock evaluated where 62% of the analyzed fecal samples were PBV-positive. The second was the high genetic variability found in field strains of ovine PBV genogroup I circulating in animals of the same sheep flock.

Investigation of enteric viruses in the feces of neotropical migratory birds captured on the coast of the State of Pará, Brazil

Migratory birds can become long-distance vectors for a wide range of microorganisms and can cause human disease, being the Brazilian coast a gateway for northern migratory birds. These animals are considered natural reservoirs of different viruses that cause important diseases, being relevant research of viral pathogens in migratory birds to epidemiology surveillance. The objective of the study was to investigate the presence of avian rotavirus (AvRV), avian reovirus (ARV) and picobirnavirus (PBV) in Neotropical migratory birds captured on the coast of Brazil. A total of 23 individual fecal samples of the migratory birds species Calidris pusilla (20 birds), Numenius phaeopus (1 bird) and Charadrius semipalmatus (2 birds) were collected. Fecal suspensions were prepared from the collected samples for subsequent extraction of double-stranded RNA (dsRNA), which was subjected to polyacrylamide gel electrophoresis (PAGE) and reverse transcription polymerase chain reaction (RT-PCR). The electrophoretic profiles were not detected by PAGE, and the amplification for the studied viruses PBV, ARV and AvRV (specie D, gene VP6 and NSP4) were negative. Positivity for AvRVD, VP7 gene was of 4.35% (1/23) for the migratory bird Calidris pusilla. After sequencing and building the tree of phylogenetic relationships avian Rotavirus Group D identified in this study was phylogenetically related and grouped into one branch, together to previously reported AvRVD from Brazil in chicken flocks with 99.8% nucleotide and 100% amino acid similarities.(AU)

Investigation of enteric viruses in the feces of neotropical migratory birds captured on the coast of the State of Pará, Brazil

Migratory birds can become long-distance vectors for a wide range of microorganisms and can cause human disease, being the Brazilian coast a gateway for northern migratory birds. These animals are considered natural reservoirs of different viruses that cause important diseases, being relevant research of viral pathogens in migratory birds to epidemiology surveillance. The objective of the study was to investigate the presence of avian rotavirus (AvRV), avian reovirus (ARV) and picobirnavirus (PBV) in Neotropical migratory birds captured on the coast of Brazil. A total of 23 individual fecal samples of the migratory birds species Calidris pusilla (20 birds), Numenius phaeopus (1 bird) and Charadrius semipalmatus (2 birds) were collected. Fecal suspensions were prepared from the collected samples for subsequent extraction of double-stranded RNA (dsRNA), which was subjected to polyacrylamide gel electrophoresis (PAGE) and reverse transcription polymerase chain reaction (RT-PCR). The electrophoretic profiles were not detected by PAGE, and the amplification for the studied viruses PBV, ARV and AvRV (specie D, gene VP6 and NSP4) were negative. Positivity for AvRVD, VP7 gene was of 4.35% (1/23) for the migratory bird Calidris pusilla. After sequencing and building the tree of phylogenetic relationships avian Rotavirus Group D identified in this study was phylogenetically related and grouped into one branch, together to previously reported AvRVD from Brazil in chicken flocks with 99.8% nucleotide and 100% amino acid similarities.

Electrophoretic RNA genomic profiles of Brazilian Picobirnavirus (PBV) strains and molecular characterization of a PBV isolated from diarrheic calf.

Picobirnavirus (PBV) belongs to the family Picobirnaviridae. PBV are a group of emerging non-enveloped viruses, with a bisegmented double-stranded RNA genome that can infect a wide range of hosts. This study reports the occurrence of PBV in fecal samples from five Brazilian dairy cattle herds. From the 289 stool samples of individual calves analyzed by silver-stained polyacrylamide gel electrophoresis (ss-PAGE) the PBV was detected in 8.3 % (24/289), of which 10.2% (18/176) had diarrheic consistency. Of the 24 positive samples in ss-PAGE, 5 (20.8%) of them showed a small electrophoretic profile and 19 (79.2%) samples had large profile. From the 24 positives samples by ss-PAGE, 15 (62.5%) were successfully amplified (201 bp) using GI specific primers targeting the RdRp gene of PBV. The analysis of nucleotide identity matrix revealed that the bovine PBV strain identified in this study, showed the highest nucleotide identity (81%) with PBV strain detected in turkey (MD-2010/HM803965). This is the first nucleotide sequence of a bovine PBV strain in the American continent and the first detection of small genome profile of PBV-like strains in bovine hosts.

Maintenance of picobirnavirus (PBV) infection in an adult orangutan (Pongo pygmaeus) and genetic diversity of excreted viral strains during a three-year period.

The present work provide data about the maintenance of picobirnavirus (PBV) infection during adulthood in a mammalian host. For this purpose PBV infection was studied in an adult orangutan (Pongo pygmaeus) by PAGE/SS, RT-PCR and nucleotide sequencing. PBV infection in the animal was asymptomatic and was characterized by interspaced silent and high/ low active viral excretion periods. The PBV strains excreted by the studied individual were identified as genogroup I and revealed a nucleotide identity among them of 64-81%. The results obtained allowed to arrive to a deeper understanding of the natural history of PBV infection, which seems to be characterized by new-born, juvenile and adult asymptomatic hosts which persistently excrete closely related strains in their feces. Consequently, picobirnaviruses could be considered frequent inhabitants of the gastrointestinal tract, leaving the question open about the molecular mechanisms governing persistent and asymptomatic coexistence within the host and the potential host suitability to maintain this relationship.

Detection of double-stranded RNA viruses in fecal samples of dogs with gastroenteritis in Rio de Janeiro, Brazil / Detecção de vírus com genoma de RNA fita dupla em fezes de cães com gastrenterite no Rio de Janeiro, Brasil

Colheram-se 163 amostras fecais no período de 1995 a 2001 para investigar a ocorrência da infecção por parvovírus e rotavírus em cães com gastrenterite utilizando-se a técnica de eletroforese em gel de poliacrilamida. Em três amostras observou-se a presença do genoma bisegmentado similar ao perfil eletroforético dos picobirnavírus (PBV) e em uma, três segmentos de RNA dupla fita, característico de picotrirnavírus. Das amostras positivas para PBV, duas foram obtidas de filhotes e uma foi positiva para parvovírus canino. Este é o primeiro relato da detecção de vírus com genoma bisegmentado em cães com diarréia no Estado do Rio de Janeiro.(AU)

Segmented double-stranded genomic RNA viruses in fecal samples from broiler chicken

Segmented double-stranded RNA (dsRNA) viruses were identified by polyacrylamide gel electrophoresis (PAGE) technique in fecal samples from broiler chicken. A total of 378 fecal samples from 1-7 weeks old chickens were analyzed. dsRNA with migration profile characteristic of avian rotavirus (AvRV), reovirus (ARV) or picobirnavirus (PBV) was identified in 32 (8.5%), 7 (1.8%) and 13 (3.4%) samples, respectively. AvRV and ARV occurred more frequently in chickens up to 1 month old and were related with enteritis signs. Considering only fecal samples of chickens with diarrhea, the AvRV was detected in 37.8% (14/37) and the ARV in 13.5% (5/37) of analyzed samples. AvRV was identified in only 1.5% (4/274) and ARV was not detected in normal feces collected from assymptomatic chickens (controls). PBV dsRNA was detected in broiler chickens from two to seven weeks old, more frequently in feces with pasty consistency. The AvRV showed great electrophoretic profile variability in the dsRNA segments and nine different electropherotypes were identified. Variation in genome pattern was not observed in either ARV or PBV.

A técnica de eletroforese em gel de poliacrilamida foi utilizada com o objetivo de identificar vírus com genoma contituído por RNA de fita dupla (dsRNA) segmentado, em material fecal de frangos de corte. Foram analisadas 378 amostras de fezes de aves, com idade entre a primeira e sétima semanas de vida, provenientes de granjas avícolas localizadas no Estado do Paraná, Brasil. dsRNA com perfil de migração característico de rotavírus (AvRV), reovírus (ARV) ou picobirnavírus (PBV), foi identificado em 32 (8,5%), 7 (1,8%) e 13 (3,4%) amostras, respectivamente. AvRV e ARV ocorreram com maior freqüência em aves com até um mês de idade e estiveram diretamente relacionados a fezes diarréicas e pastosas, provenientes de aves com sinais clínicos de enterite. Considerando-se apenas as amostras de fezes colhidas em aves com diarréia, o AvRV foi detectado em 37,8% (14/37) e o ARV em 13,5% (5/37) da amostragem analisada. Em fezes com aspectos normais (controle) obtidas de aves clinicamente sadias, o AvRV foi identificado em apenas 1,5% (4/274) e o ARV não foi detectado. O ácido nucléico do PBV foi detectado com maior freqüência em fezes pastosas colhidas de aves com duas a sete semanas de vida. O AvRV apresentou grande variabilidade eletroforética dos segmentos de dsRNA, tendo sido identificados nove eletroferotipos distintos. Não foram observadas variações no perfil genômico nas amostras de ARV e também de PBV.

Enteric virus with segmented double-stranded RNA genome in broiler chicken: Rotavirus, Reovirus and Picobirnavirus / Virus entéricos RNA fita dupla, segmentado, em aves: Rotavírus, Reovírus e Picobirnavírus

Enteric infections account for considerable economic losses to the poultry industry through weight loss, low food conversion, direct and indirect expenses with treatments and increased death rates. Poultry intestinal pathologies, either with local or general manifestations, can be caused by bacteria, protozoa or virus, acting alone or in association. Regarding viral etiology, several genera have been isolated from poultry with enteric disease. However, two genera from the Reoviridae family, the rotavirus and the reovirus are found more frequently in broiler chicken and/or laying hen feces. These viruses have been associated with clinical signs of enteritis in most epidemiological research. This revision aims to present some topics on the etiological agents (rotavirus, reovirus and picobirnavirus), the clinical disease and the diagnostic and control methods and prophylaxis of the infection.

As infecções entéricas são responsáveis por consideráveis prejuízos econômicos à indústria avícola representados por perda de peso, baixa conversão alimentar, custos diretos e indiretos com tratamentos e por aumento na taxa de mortalidade. As patologias intestinais em aves, tanto com manifestação local quanto geral, podem ser determinadas por bactérias, protozoários e vírus, atuando de forma isolada ou em associação. Com relação a etiologia virai, vários gêneros têm sido isolados a partir de aves com enteropatias. Porém, dois gêneros na família Reoviridae, o rotavírus e o reovírus são encontrados com maior freqüência em fezes de frangos de corte e/ou galinhas poedeiras. Na maioria dos inquéritos epidemiológicos esses vírus estão associados a sinais clínicos de enterite. Esta revisão tem por objetivo apresentar alguns tópicos relativos aos agentes etiológicos (Rotavírus, Reovírus e Picobirnavírus), à doença clínica e aos métodos de diagnóstico, controle e profilaxia da infecção.

Enteric virus with segmented double-stranded RNA genome in broiler chicken: Rotavirus, Reovirus and Picobirnavirus / Virus entéricos RNA fita dupla, segmentado, em aves: Rotavírus, Reovírus e Picobirnavírus

Enteric infections account for considerable economic losses to the poultry industry through weight loss, low food conversion, direct and indirect expenses with treatments and increased death rates. Poultry intestinal pathologies, either with local or general manifestations, can be caused by bacteria, protozoa or virus, acting alone or in association. Regarding viral etiology, several genera have been isolated from poultry with enteric disease. However, two genera from the Reoviridae family, the rotavirus and the reovirus are found more frequently in broiler chicken and/or laying hen feces. These viruses have been associated with clinical signs of enteritis in most epidemiological research. This revision aims to present some topics on the etiological agents (rotavirus, reovirus and picobirnavirus), the clinical disease and the diagnostic and control methods and prophylaxis of the infection.  

As infecções entéricas são responsáveis por consideráveis prejuízos econômicos à indústria avícola representados por perda de peso, baixa conversão alimentar, custos diretos e indiretos com tratamentos e por aumento na taxa de mortalidade. As patologias intestinais em aves, tanto com manifestação local quanto geral, podem ser determinadas por bactérias, protozoários e vírus, atuando de forma isolada ou em associação. Com relação a etiologia virai, vários gêneros têm sido isolados a partir de aves com enteropatias. Porém, dois gêneros na família Reoviridae, o rotavírus e o reovírus são encontrados com maior freqüência em fezes de frangos de corte e/ou galinhas poedeiras. Na maioria dos inquéritos epidemiológicos esses vírus estão associados a sinais clínicos de enterite. Esta revisão tem por objetivo apresentar alguns tópicos relativos aos agentes etiológicos (Rotavírus, Reovírus e Picobirnavírus), à doença clínica e aos métodos de diagnóstico, controle e profilaxia da infecção.  

Enteric virus with segmented double-stranded RNA genome in broiler chicken: Rotavirus, Reovirus and Picobirnavirus / Virus entéricos RNA fita dupla, segmentado, em aves: Rotavírus, Reovírus e Picobirnavírus

Enteric infections account for considerable economic losses to the poultry industry through weight loss, low food conversion, direct and indirect expenses with treatments and increased death rates. Poultry intestinal pathologies, either with local or general manifestations, can be caused by bacteria, protozoa or virus, acting alone or in association. Regarding viral etiology, several genera have been isolated from poultry with enteric disease. However, two genera from the Reoviridae family, the rotavirus and the reovirus are found more frequently in broiler chicken and/or laying hen feces. These viruses have been associated with clinical signs of enteritis in most epidemiological research. This revision aims to present some topics on the etiological agents (rotavirus, reovirus and picobirnavirus), the clinical disease and the diagnostic and control methods and prophylaxis of the infection.  

As infecções entéricas são responsáveis por consideráveis prejuízos econômicos à indústria avícola representados por perda de peso, baixa conversão alimentar, custos diretos e indiretos com tratamentos e por aumento na taxa de mortalidade. As patologias intestinais em aves, tanto com manifestação local quanto geral, podem ser determinadas por bactérias, protozoários e vírus, atuando de forma isolada ou em associação. Com relação a etiologia virai, vários gêneros têm sido isolados a partir de aves com enteropatias. Porém, dois gêneros na família Reoviridae, o rotavírus e o reovírus são encontrados com maior freqûência em fezes de frangos de corte e/ou galinhas poedeiras. Na maioria dos inquéritos epidemiológicos esses vírus estão associados a sinais clínicos de enterite. Esta revisão tem por objetivo apresentar alguns tópicos relativos aos agentes etiológicos (Rotavírus, Reovírus e Picobirnavírus), à doença clínica e aos métodos de diagnóstico, controle e profilaxia da infecção.