Archives of Virology最新文献

Following their identification in French cereals in 2022–2023, the complete genome sequences of two isolates of wheat mosaic virus (WMoV, Emaravirus tritici) were determined. The French isolates showed the closest relationship to Ohio group isolates, with 92% (P7) to 98% (P1) amino acid sequence identity in their proteins. Notably, the two French isolates were found to differ significantly in their RNA7, and one of them was found to possess two RNA5 and three RNA6 segments, a feature not previously reported for WMoV. This represents the first identification of WMoV in the European Union, and the data reported here significantly extend our knowledge about the genome composition and diversity of this virus.

Leishmania RNA virus 2 (LRV2) has emerged as a potential molecular co-determinant of clinical outcomes in Leishmania major infections, particularly within the Old-World cutaneous leishmaniasis (CL) belt. Recent molecular investigations from Iran and adjacent endemic regions (2024-2025) have revealed extensive LRV2 diversity and phylogeographic structure. However, the lack of standardized assays, incomplete clinical metadata, and inconsistent reporting frameworks have hindered translation of detection findings into actionable public-health insights. This commentary synthesizes these findings and proposes a six-point, standards-based micro-protocol for harmonizing molecular detection, metadata collection, and clinical outcome recording, aimed at enhancing decision-useful surveillance and global comparability

In Japan, only one satsuma dwarf virus (SDV) isolate has been fully sequenced to date. This study provides complete genome sequences of six SDV isolates for which only partial sequences had been determined and three for which no sequence data were available. Among all known isolates, nucleotide sequence identity was found to range from 67.9 to 98.6% for RNA1 and from 67.9 to 98.8% for RNA2. The amino acid sequence identity in the coat protein (CP) ranged from 76.9 to 99.2%. Phylogenetic analysis revealed that five of the nine newly sequenced isolates clustered with the citrus mosaic virus (CiMV) strain, two with the SDV strain, and one each with the navel orange infectious mottling virus (NIMV) and hyuganatsu virus (HV) strains.

In this study, the presence of a betacoronavirus (species Betacoronavirus erinacei, genus Betacoronavirus, family Coronaviridae) was investigated in faecal samples collected from northern white-breasted hedgehogs (Erinaceus roumanicus) in different sampling areas in Hungary using reverse transcription PCR (RT-PCR) and sequencing methods. A total of 23 (27.4%) of the 84 specimens were positive for betacoronaviruses (PX460030-PX460052), and the region of the viral genome encoding the complete spike protein was sequenced for eight of the positive samples. The complete spike genes from these eight specimens showed 91–94% nucleotide (nt) and 92–94% amino acid (aa) sequence identity to each other and 86–91% nt and 87–92% aa sequence identity to the other European hedgehog coronavirus strains. Hedgehog betacoronavirus is a common and widespread infectious agent in the three hedgehog species (E. europaeus, E. amurensis, and, based on this study, E. roumanicus) studied in Europe and Asia so far, with geographical and probably host-species-specific genetic lineages.

Single-cycle viruses, which lack essential genes for virus replication, demonstrate high protective efficacy and safety, making them promising candidates for commercial vaccines. However, their lack of replication capacity presents a difficulty for large-scale vaccine production. In this study, we aimed to enhance viral replication by utilizing drugs targeting microtubule dynamics, which play a crucial role in maintaining cell structure, transporting materials, and facilitating the movement of viral particles within the host cell during virus infection. To identify optimal drug concentrations and assess viral replication capacity, we constructed the single-cycle viral hemorrhagic septicemia virus rVHSV-A-MetLuc-GΔTM, which contains a luciferase reporter gene. Using this construct, both drugs enhanced the production of single-cycle viruses in fish cells at a concentration of 100 nM without causing cytotoxicity. Furthermore, we identified the mechanism by which viral replication is increased, which involves upregulation of the c-Fos and c-Jun genes. This indicates that the transcription factor AP-1 plays a key role in this process. This study shows that appropriate treatment with colchicine and paclitaxel, which influence microtubule dynamics, can enhance the replication capacity of single-cycle viruses. This presents opportunities to increase the cost-effectiveness of single-cycle and attenuated virus-based vaccines for industrial use.

We analyzed the dsRNA profiles of Trichoderma spp. and identified a novel mycovirus from Trichoderma harzianum strain NFCF419. Phylogenetic and genomic analysis suggested that this virus is a novel member of the family Alternaviridae. Next-generation sequencing (NGS) analysis revealed that this virus consisted of four genome segments. The complete genome sequences of the segments were determined by NGS, and the NGS results were confirmed by manual sequencing of RT-PCR amplicons using specific primer pairs. 5’- and 3’-RACE was performed to determine the terminal sequences of each segment. The genome segments were found to be 3,572 bp (dsRNA1), 2,552 bp (dsRNA2), 2,593 bp (dsRNA3), and 1,484 bp (dsRNA4) in size. The largest segment (dsRNA1) contains a single open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRP). dsRNA2, 3, and 4 each contain a single ORF encoding a putative methyltransferase, a coat protein, and a hypothetical protein with unknown function, respectively. Evaluation of the genome organization, analysis of the deduced amino acid sequence of the RdRP, and phylogenetic analysis indicated that this virus is a new member of the genus Alternavirus in the family Alternaviridae. Accordingly, we designated this novel mycovirus "Trichoderma harzianum alternavirus 1" (ThAV1). This is the first report of a mycovirus of the family Alternaviridae that infects a member of the genus Trichoderma.

Dahlia mosaic virus (DMV) and dahlia common mosaic virus (DCMV), members of the genus Caulimovirus, are associated with dahlia mosaic disease and are prevalent in dahlia plants in the USA and in several other parts of the world. To resolve a discrepancy in the publicly available genomic sequence of DMV and its taxonomic status with respect to DCMV, the complete genome sequences of several DMV and DCMV isolates from different regions of the USA were determined. Based on this sequence analysis, we resolved a discrepancy in the previously reported DMV sequence, confirmed that DMV possesses a genome structure and organization that is typical of a caulimovirus, and found that it shares 81% identity in the polyprotein coding sequence and 85% in the RT and RNase H domains of the polyprotein with DCMV. Greater sequence divergence was observed in the remainder of their genomes. As per the guidelines for demarcation of caulimoviruses at the species level by the International Committee on Taxonomy of Viruses, we propose that DMV and DCMV should be considered variants of the same virus.

Highly pathogenic avian influenza (HPAI) H5N8 virus, first identified in late 2016 in Egypt, continues to circulate and has replaced the previously dominant HPAI H5N1 virus of clade 2.2.1. In this study, HPAI H5N8 was detected on 23 commercial poultry farms in Egypt. Complete genome sequences of three isolates collected in 2021 were obtained using next-generation sequencing (NGS) and subjected to genetic characterization. Phylogenetic analysis showed these isolates to belong to clade 2.3.4.4b, comprising two genotypes: EA-2021-Q and EA-2020-A. Molecular analysis of the haemagglutinin (HA) protein revealed the presence of T156A and V538A substitutions in the duck isolate and an N183S substitution in the chicken isolate. Several additional nonsynonymous mutations were identified, including 147I and 504V in the PB2 protein, 127V, 672L, and 550L in the PA protein, 64F and 69P in the M2 protein, and 42S in the NS1 protein. Comparative analysis of HA antigenic sites between these isolates and the human vaccine against H5N8 revealed four nonsynonymous mutations: S141P, A154N, D45N, and V174I. Notably, the HA sequences of the studied isolates shared 98.7–99.4% amino acid sequence identity, and the NA sequences shared 96.1–97.1% identity to those of the 2.3.4.4b candidate human H5N8 vaccine strain (CVV) A/Astrakhan/3212/2020-like. These findings underscore the importance of continuous monitoring of the genetic evolution of avian influenza viruses to guide updates of candidate vaccine strains. Furthermore, the high similarity between the detected isolates and a zoonotic Russian H5N8 wild-type strain highlights the potential risk of cross-species transmission and possible human infection.

The complete sequence of Curcuma alismatifolia bract virus (CurABV) from the city of Zhangzhou in Fujian Province, China, was determined by high-throughput sequencing. The viral genome consists of 8273 nucleotides (nt) and encodes a large polyprotein of 2634 amino acids (aa). In silico analysis predicted that this polyprotein is cleaved by two viral proteases into nine mature proteins. Sequence comparisons showed that CurABV shares 48.60-74.40% nt and 48.71-71.49% aa sequence identity with other macluraviruses in the coat protein (CP) gene. Phylogenetic analysis showed that CurABV clustered with representative members of the genus Macluravirus. These data suggest that CurABV is a new member of the genus Macluravirus. To our knowledge, this is the first report of the complete genome sequence of a macluravirus infecting C. alismatifolia.

Few studies have examined adenoviruses (AdVs) in bats from the U.S.; therefore, we targeted a fragment of the adenoviral DNA polymerase gene from 94 fecal samples from nine bat species in Texas. Three samples from Antrozous pallidus had identical sequences, but these differed from those found in one Myotis yumanensis and one Tadarida brasiliensis sample. Phylogenetic analysis showed that these DNA sequences were most similar to those of a previously described AdV found in Myotis velifer in Oklahoma. Each of these sequences differed by more than > 12% from those of any currently classified AdVs and by more than 10% from that of a currently unclassified AdV isolate from Myotis myotis.