![]() Typing of enteroviruses relies on molecular characterization of the capsid-encoding region (Blomqvist and Roivainen, 2016). Enteroviruses cause a wide spectrum of human diseases, with clinical signs ranging from mild febrile illness, such as the common cold, to severe forms, such as acute haemorrhagic conjunctivitis, myocarditis, encephalitis, and acute flaccid paralysis (Tapparel et al., 2013).Ĭurrently, more than 20 types of EV-Cs have been identified (Knowles et al., 2012), including the three serotypes of poliovirus (PV-1 to −3) that can induce severe and potentially fatal cases of poliomyelitis in humans. P1 gives rise to the four structural capsid proteins (VP1–VP4) while P2 and P3 generate non-structural proteins involved in the viral cycle. The polyprotein encoded by this open reading frame is first cleaved into three precursors (P1–P3) that are subsequently cleaved into functional proteins. The virions contain one copy of the genome, which is about 7500 nucleotides in length and consists of two untranslated regions (5′- and 3′-UTR) flanking a unique large open reading frame. The members of the Enterovirus species C (EV-C), genus Enterovirus, family Picornaviridae, are non-enveloped viruses with a single positive strand RNA genome. By decreasing the workload compared to classical Sanger-based techniques, this method will serve as a precious tool for sequencing large panels of EV-Cs isolated in cell cultures during environmental surveillance or from patients, including vaccine-derived polioviruses. It was also able to discriminate reads from closely related viruses in mixtures. It can be used to determine full-length genome sequences through de novo assembly of thousands of reads. The method was assessed on a panel of EV-Cs belonging to a wide-range of types. ![]() The four amplicons were then pooled and purified prior to being sequenced by a high-throughput technique. Four overlapping fragments were produced separately by RT-PCR performed with generic primers. A simple method was developed to quickly sequence the entire genome of EV-C isolates. Therefore, identification and characterization of circulating EV-C strains require the sequencing of different genomic regions. Biodiversity and evolution of EV-C genomes are shaped by frequent recombination events. Enterovirus species C (EV-C) consists of more than 20 types, among which the three serotypes of polioviruses, the etiological agents of poliomyelitis, are included. This study of WSHBV genetic diversity should facilitate the development of molecular markers for future identification of genotypes and provide evidence in future investigations of possible differential disease outcomes.Enteroviruses are among the most common viruses infecting humans and can cause diverse clinical syndromes ranging from minor febrile illness to severe and potentially fatal diseases. Although the levels of variation we observed do not meet the criteria used to define sub/genotypes of human and avian hepadnaviruses, we identified geographically associated genome variation in the pre-S and spacer domain sufficient to define five WSHBV haplotypes. The observed predominance of p1/s3 mutations in this region is indicative of adaptive change in the polymerase open reading frame (ORF), while, at the same time, the surface ORF is under purifying selection. Notably, most non-synonymous substitutions were found to cluster in the pre-S/spacer overlap region, which is relevant for both viral entry and replication. Phylogenetic analysis of the WSHBV genome identified phylogeographical clustering reminiscent of that observed with human hepatitis B virus genotypes. ![]() Templates from 27 virus-positive fish were amplified and sequenced using a primer-specific, circular long-range amplification method coupled with amplicon sequencing on the Illumina MiSeq. Copy number in plasma and in liver tissue was estimated via qPCR. We identified WSHBV-positive white sucker inhabiting tributaries of Lake Michigan, Lake Superior, Lake Erie (USA), and Lake Athabasca (Canada). Given the relevance of genomic diversity to disease outcome for the orthohepadnaviruses, we sought to characterize genomic variation in WSHBV and determine how it is structured among watersheds. At present, the host range of WSHBV and its impact on fish health are unknown, and neither genetic diversity nor association with fish health have been studied in any parahepadnavirus. The white sucker hepatitis B virus (WSHBV) was first described in the white sucker ( Catostomus commersonii), a freshwater teleost, and belongs to the genus Parahepadnavirus. Hepatitis B viruses belong to a family of circular, double-stranded DNA viruses that infect a range of organisms, with host responses that vary from mild infection to chronic infection and cancer.
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