Archives of Virology最新文献

In this study, we examined samples from 135 deceased ducks, collected from 27 farms across South Korea between 2022 and 2023, and determined that the positivity rate for duck circovirus (DuCV) was 66.7%. Whole-genome sequencing was performed on 18 DuCV strains from the DuCV-positive farms. Phylogenetic analysis revealed that 13 of the 18 strains belonged to genotype Ib, while the remaining five strains belonged to genotype Id, marking the first identification of this genotype in Korea. Further phylogenetic and recombination analysis showed that the DuCV-Ib strains could be categorized into two distinct sublineages. Notably, two genotype Ib strains appear to have originated through intra-sublineage recombination. In light of the high prevalence, genetic diversity, and ongoing evolution of DuCVs in domestic duck populations in Korea, these findings underscore the importance of ongoing surveillance, as well as enhanced disease prevention and control measures.

A novel phage specific for Klebsiella pneumoniae, named vB_KpnS_2146 − 302, was isolated from hospital wastewater. Through transmission electron microscopy observation and genomic analysis, this phage was found to belong to the genus Webervirus in the family Drexlerviridae. Biological studies showed that vB_KpnS_2146 − 302 has a narrow host range and exhibits specific lytic activity against K. pneumoniae. A one-step growth curve showed a latency period of 10 minutes and a burst size of 1125 PFU/cell. The phage remained stable within a pH range of 3–9 and a temperature range of 26–60°C. Whole-genome sequencing analysis showed that the double-stranded DNA genome of vB_KpnS_2146 − 302 is 50,299 bp in length and contains 76 open reading frames. Experiments in which cells were treated with proteinase K or periodate suggested that the carbohydrate structure of K. pneumoniae is involved in the adsorption of this phage. This study shows that phage vB_KpnS_2146 − 302 might be a new candidate for the development of phage therapy against K. pneumoniae infections.

Acute viral hepatitis (AVH) caused by hepatitis A virus (HAV), hepatitis E virus (HEV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) often presents with similar clinical and biochemical features. However, serological cross-reactivity among these viruses poses significant diagnostic challenges, potentially leading to misclassification, inappropriate management, and unreliable epidemiological data. To review the immunological mechanisms contributing to serological cross-reactivity in AVH and highlight the diagnostic and clinical implications, with a focus on the importance of molecular confirmation. A structured literature review was conducted using the PubMed, EMBASE, Scopus, and Web of Science databases. Keywords included terms related to cross-reactivity, acute hepatitis, serological testing, molecular diagnostics, and specific viral agents. Peer-reviewed studies published in English up to 2025 were included. Cross-reactivity in AVH is primarily driven by polyclonal B-cell activation, antibody polyreactivity, and T-cell receptor cross-specificity. Studies report that up to 33.3% of anti-HEV IgM–positive samples also test positive for EBV or CMV IgM, despite negative PCR confirmation. This overlap is particularly problematic in immunocompromised individuals and pregnant women, where accurate pathogen identification is critical. While PCR offers superior specificity and sensitivity, its implementation is limited by cost and accessibility in low-resource settings. Serological cross-reactivity in acute hepatitis significantly impacts diagnostic precision and clinical decision-making. Incorporating molecular testing, especially PCR, into diagnostic workflows is essential to ensure accurate diagnosis, particularly in high-risk populations.

Newcastle disease virus (NDV) and H9N2 avian influenza virus (AIV) have a severe impact on the poultry industry. This Iranian study evaluated Payavax G79®, an inactivated bivalent vaccine, in broiler chickens across five provinces. Vaccinated chicks showed robust antibody responses to both viruses via HI tests at 25 and 32 days post-vaccination. The vaccine provided complete protection against challenge with velogenic NDV genotype VII. However, H9N2 infection occurred on three farms, with 2% mortality. Molecular analysis of NDV isolates revealed amino acid substitutions in the hemagglutinin-neuraminidase protein that potentially enhance antigenicity. This study shows that Payavax G79® is highly immunogenic and provides significant protection against both NDV and H9N2 AIV under field conditions in Iran.

Newcastle disease (ND), caused by virulent Newcastle disease virus (NDV), poses a major global threat to the poultry industry. ND vaccines have been used for nearly 70 years for disease prevention and control, and much is known about adaptive immune responses to infection and vaccination. However, our current knowledge remains incomplete and biased. While humoral immunity, especially regarding the induction of hemagglutination-inhibiting and virus-neutralizing antibodies, has been studied extensively, research on mucosal and cellular immunity has been more limited, despite their critical roles in restricting and clearing viral infection. Furthermore, fundamental questions persist even for humoral responses, such as the role of antibodies against viral internal proteins, the mechanisms of virus neutralization by antibodies, and the effect of antibody production on viral evolution. This review systematically summarizes existing knowledge on adaptive immunity to NDV infection, encompassing humoral, mucosal, and cellular aspects. It also highlights key gaps in our understanding of immune responses in poultry, which is important for developing novel vaccines and control strategies.

Plum pox virus (PPV), a significant member of the genus Potyvirus, represents a global agricultural challenge, causing significant economic losses and threatening fruit farming due to its easy transmission to most Prunus species. Here, we present the high-resolution structural characterization of PPV using cryo-electron microscopy (cryo-EM). The reconstructed structure at 2.9 Å reveals a filamentous virion with a helical assembly formed by the coat protein (CP), which encapsidates a single-stranded RNA (ssRNA) genome. The structure of the CP core shows remarkable conservation with other potyviruses, with an RNA binding site and inter-subunit interactions mediated in part by the N-terminal arm, which is confirmed here to have a disordered structure. Mass spectrometry analysis identified numerous post-translational modifications, mostly phosphorylation, primarily in the flexible N-terminal region. In silico predictions revealed intrinsically disordered regions, which is compatible with the amyloidogenic properties of the CP. These results provide new insights into the architecture and assembly of PPV, offering a basis for future studies and, possibly, antiviral strategies.

Chloroviruses were first described in the late 1970s, and this opened a new area in virology. These giant DNA viruses, capable of infecting unicellular eukaryotic algae, are ubiquitous in inland waters and have been isolated from various locations worldwide, revealing extensive and complex genetic diversity. These viruses belong to the genus Chlorovirus, family Phycodnaviridae, order Algavirales. Currently, only six species are officially recognized by the International Committee on Taxonomy of Viruses (ICTV), but recent data from our group suggest the existence of many others. In this work, we present the lines of evidence supporting the creation of subgenera within the genus Chlorovirus, as well as robust criteria for the classification of more than 100 viral isolates. We submitted an official taxonomic proposal to the ICTV for the creation of the subgenera “Alphachlorovirus”, “Betachlorovirus”, and “Gammachlorovirus” to classify the viruses that have historically been called NC64A-virus, Pbi-virus, and SAG-virus, respectively. Each subgenus, supported by both phylogenomic and comparative genomic analysis, comprises a total of 20 species to date. We hope that the criteria presented here can serve as a basis for taxonomic advances in other groups of giant algal viruses. The taxonomic proposal is still under consideration by the ICTV.

Akabane virus (AKAV), the etiological agent of Akabane disease, is known to induce congenital malformations and neuropathologies in the fetuses of pregnant cattle and sheep. To analyze the changes in gene expression patterns that occur in AKAV-infected cells, two types of primary bovine cells – primary bovine testicular Sertoli cells (BTSCs) and primary bovine joint synovial cells (BJSCs) – were selected. These cells were confirmed to be infected by AKAV strain TJ2016. Subsequently, RNA-sequencing technology was employed to analyze the transcriptomic profiles of AKAV-infected BTSCs and BJSCs, as well as Madin-Darby ovine kidney (MDOK) cells. The AKAV-infected cells exhibited activation of antiviral signaling pathways. Notably, there was upregulation of the expression levels of interferon-stimulated genes, as well as genes related to inflammation and cytokines. IL-1β, TNF-α, CXCL8, CCL2, and Rnd1 were found to be significantly upregulated in AKAV-infected cells. Moreover, Rnd1 was found to inhibit the replication of AKAV. Because TNF-α plays an important role in the induction of Rnd1, this provides additional evidence for the regulation and function of Rnd1.

Goatpox is a highly contagious viral disease that poses a significant threat to the health of goats and other small ruminants. Here, we report for the first time that the murine osteoblastic cell line MC3T3-E1 supports productive GTPV infection, as demonstrated by Western blotting, indirect immunofluorescence assay, and flow cytometry. RNA sequencing revealed thousands of differentially expressed genes (DEGs). Signaling pathways and functions of the DEGs were analyzed using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes. Real-time quantitative PCR further confirmed the expression of several DEGs. The present study extends the host range for GTPV replication and mechanistic investigations.

Previous studies on the genetic diversity of Lassa virus (LASV) have often relied on sequences containing undetermined nucleotides. In this study, we analyzed open reading frame (ORF) sequences free of undetermined nucleotides to assess LASV diversity with improved accuracy. The calculated pairwise identity was ≥ 68% for the polymerase, ≥ 74% for the nucleoprotein (NP), and ≥ 75% for the glycoprotein (GP) genes. LASV strains were classified into seven established lineages. Notably, lineage VI (represented by strain KT992435.1_KAK-428) exhibited phylogenetic relatedness to all other lineages, suggesting that it may retain ancestral traits. This observation underscores the potential evolutionary significance of its rodent host, Hylomyscus pamfi. A multiple sequence alignment of the GP gene revealed a unique codon insertion present only in lineages IV and V. The GP from these two lineages showed a predicted antigenicity score of 0.66, which is lower than the maximum scores observed in other lineages. Nonetheless, all lineage representatives were predicted to be non-allergenic and non-toxic and possessed a moderate density of B- and T-cell epitopes with ≥ 90% conservation. Considering the observed genetic divergence, antigenic variation, and epitope conservation, lineage VI (KAK-428) is proposed as a potential target for the development of a broadly protective LASV vaccine.