We recently discovered a novel member of the family Arteriviridae, hedgehog arterivirus 1 (HhAV-1), in the brains of hedgehogs with fatal encephalitis. In this study, we classified this virus and investigated its intrahost genomic diversity using next-generation sequencing. We sequenced HhAV-1 genomes from specimens from seven hedgehogs (two males and five females) with signs of encephalitis that were collected in Buckinghamshire, Gloucestershire, and Cambridgeshire, England, and had died or been euthanised between 2013 and 2024. Analysis of the intrahost populations of these seven HhAV-1 isolates and a previously described isolate revealed the presence of single-nucleotide polymorphisms (SNPs), which were most frequent in open reading frames 5, 6, and 7, encoding glycoprotein 5, the membrane protein, and the nucleocapsid protein. Pairwise comparisons of the eight HhAV-1 variants showed that the nucleotide sequence identity values in their combined complete coding sequences ranged from 76.2% to 100%. The eight HhAV-1 variants also shared at least 82.8% amino acid sequence identity in five domains that are involved in replication and are used for the classification of nidoviruses: 3CLpro, NiRAN, RdRp, ZBD, and HEL1. In a replicase-based phylogenetic tree of members of the family Arteriviridae, the HhAV-1 variants formed a sister cluster to African pouched rat arterivirus. A DEmARC-based pairwise distance analysis indicated that these viruses may comprise a new species, for which we propose the name "Xiarterivirus erinaceid", in a new genus in the subfamily Heroarterivirinae.

The aim of this study was to detect chicken parvovirus (ChPV) and turkey parvovirus (TuPV) on Turkish poultry farms and examine the molecular epidemiology of these viruses. In 2023, a total of 1,060 fecal samples were collected from 76 broiler farms and 30 turkey farms across various regions of Turkiye. The overall positivity rate was 72.3% (55/76) in broiler flocks and 70% (21/30) in turkey flocks. Among these, the positivity rate was 35% (7/20) in birds showing no signs of enteritis. The findings of this study suggest that, depending on the genetic variability of regional strains or the viral load, nested-PCR-based methods may prove more effective than single-step PCR for detecting ChPV and TuPV cases. Therefore, it is recommended to incorporate nested PCR in molecular epidemiological studies to minimize the risk of overlooking positive cases. Phylogenetic analysis of the VP1, VP2, and complete genome sequences of TUR/2023/ChPV and TR/2023/TuPV revealed that both strains clustered with American strains in distinct lineages. Analysis using the recombination detection programs RDP4.0 and SimPlot 3.5.1 strongly suggested that TUR/2023/ChPV may be a recombinant of strains from China and Brazil. Despite the observed genetic variability in the VP2 protein, an examination of B-cell epitopes showed a high degree of similarity between ChPV and TuPV strains. This study represents the first documentation of the emergence and prevalence of TuPVs in Turkiye, providing complete genome sequences for both ChPV and TuPV. Given the high prevalence and genetic diversity of these viruses and their presence in clinically asymptomatic birds, it is crucial for stakeholders in the poultry industry to implement regular flock screenings for these and similar viral pathogens. Proactive measures like these are essential for mitigating the economic impact of these important pathogens and developing effective preventive strategies.

A new virus was found in Sauropus androgynus plants with curled and yellow leaves in China and tentatively named "Sauropus androgynus virus" (SaV). The complete genome of SaV is an 8007-nucleotide-long (+)RNA, excluding the 3'-poly(A) tail, and contains five open reading frames. Both pairwise comparisons and phylogenetic analysis of the putative replicase and coat proteins showed that SaV has a high level of sequence similarity to members of the genus Allexivirus of the family Alphaflexiviridae. This is the first report of an allexivirus in Sauropus androgynus.

Lumpy skin disease (LSD) has emerged as a threat to cattle production in Asia, and India has been facing LSD epidemics since 2019. Although water buffalo (Bubalus bubalis) is susceptible to natural LSDV infection, there have been no confirmed reports of LSDV infection in water buffalo in India. In this study, we investigated suspected cases of LSD in water buffaloes from 12 Indian states and one union territory during 2020-2023. Buffaloes showed mild to moderate clinical disease with fever and nodular skin lesions, but most remained asymptomatic. Eighteen of 177 (10.18%) buffaloes in 12 districts in three states tested positive for LSDV by real-time PCR, while 22 of 57 (38.59%) from nine districts in six states tested positive for LSDV-neutralizing antibodies, demonstrating the prevalence of LSDV infection in buffaloes over a wider geographic area. Successful virus isolation and nucleotide sequencing confirmed natural LSDV infection in buffaloes. Phylogenetic analysis of complete GPCR, RPO30, and EEV gene sequences revealed the presence of wild-type strains of two divergent LSDV lineages (1.2.1 and 1.2.2) in buffaloes. The 1.2.2 strains were closely related to the dominant LSDV strain (subcluster 1.2.2, KSGP-like) circulating in India, while the 1.2.1 strains clustered with strains from the Middle East, Europe, and the Balkans, confirming that there have been multiple introductions of LSDV into India. The detection of viruses with identical sequences in buffaloes and local cattle implied that the LSDV strain found in buffaloes is probably of cattle origin. We also found evidence of cocirculation of LSDV 1.2.1 and 1.2.2 wild-type strains in the same area, highlighting the importance of LSDV surveillance and genetic analysis. This is the first confirmed report of natural LSDV infection in water buffaloes in India. Further investigations are needed to assess the impact of LSDV infection in buffalo production and the role of buffalo in LSD epidemiology.

Members of the fungal genus Stagonosporopsis are important plant pathogens that can cause severe disease on a wide range of economically important plants and crops. Here, a novel victorivirus, tentatively named "Stagonosporopsis citrulli victorivirus 1" (SciVV1), was isolated from S. citrulli isolate HS2-8. The SciVV1 genome is 5,163 nucleotides in length, with a predicted GC content of 63.85%, and contains two open reading frames (ORF1 and ORF2), which overlap at an AUGA sequence. ORF1 and ORF2 are predicted to encode a coat protein (CP) and an RNA-dependent RNA polymerase (RdRp). A phylogenetic tree based on RdRp amino acid (aa) sequences showed that SciVV1 clustered together with members of the genus Victorivirus in the family Pseudototiviridae. Our results indicate that SciVV1 is a novel victorivirus. This is the first report of the complete genome sequence of SciVV1 infecting S. citrulli.

Targeting interactions between a virus and a host protein is one of the important approaches to developing antiviral therapies. We previously identified host nucleolin as a novel interacting partner of the influenza A virus nucleoprotein, and it was demonstrated that this interaction restricts virus replication. In the current study, we examined the interaction of nucleolin with the viral nucleoprotein at the domain and amino acid levels using in vitro and in silico approaches. Both approaches demonstrated a direct and specific interaction between these two proteins. Furthermore, it was observed that previous pandemic strains of influenza A virus had specific amino acid residues in their nucleoproteins that were predicted to be critical for interaction with nucleolin. This preliminary analysis provides insights into the binding process, which could be explored for developing antiviral strategies.

Campylobacter jejuni is a leading cause of foodborne illness worldwide. The application of bacteriophages offers a promising approach to specifically target and reduce C. jejuni contamination in food products. In this study, two C. jejuni phages were characterized, and their ability to inhibit bacterial growth in combination with ethylenediaminetetraacetic acid (EDTA) was investigated. Both phages exhibited tolerance to a wide range of temperature (4-60°C) and pH (3-9). Phage vB_CjeM-PC10 and vB_CjeM-PC22 were found to have a latent period of 30 min and 20 min and a burst size of 7 and 35 PFU/cell, respectively. Phage vB_CjeM-PC10 has a linear double-stranded DNA (dsDNA) genome of 51,148 bp with 77 ORFs and 29% GC content. Phage vB_CjeM-PC22 has a circular dsDNA genome of 32,543 bp with 56 ORFs and 28% GC content. At 42°C, the combination of these phages (MOI = 10) and EDTA decreased the count of viable C. jejuni by 5.2 log10 and inhibited the regrowth of resistant cells for 48 h. At 4°C, phage vB_CjeM-PC10 alone (MOI = 1000) reduced the count of viable C. jejuni by 3 log10 in brain heart infusion (BHI) broth and 2 log10 on chicken skin after incubation for 48 h. Although these phages were effective against C. jejuni, they cannot be utilized directly for food safety applications because they are lysogenic. Nevertheless, these findings expand the genome library of C. jejuni phages and enrich data resources by highlighting potential strategies for controlling C. jejuni infections.

In this study, a novel virus isolated from Nigrospora oryzae, tentatively named "Nigrospora oryzae mycovirus 1" (NoMyV1), was identified. NoMyV1 has a non-segmented dsRNA genome that is 2891 bp in length and contains two non-overlapping open reading frames (ORF1 and 2). ORF1 encodes a protein with sequence similarity to the putative capsid proteins or hypothetical proteins of other unclassified viruses, while ORF2 encodes an RNA-dependent RNA polymerase (RdRp). Sequence comparisons showed that NoMyV1 was most similar to Penicillium janczewskii Beauveria bassiana-like virus 1 (PjBblV1), with 76.12% amino acid sequence identity in the RdRp. In a phylogenetic analysis based on RdRp sequences, NoMyV1 was found to cluster with several other unclassified viruses for which a new genus, "Unirnavirus", which is distinct from the family Partitiviridae, has been proposed. Thus, we conclude that NoMyV1 is a novel member of the proposed genus "Unirnavirus".

Canine parvovirus (CPV) is a significant threat to canines and is widely distributed worldwide. While vaccination is currently the most effective preventive measure, existing vaccines are not able to offer comprehensive and dependable protection against CPV infection. Hence, there is a need to explore alternative or complementary strategies to tackle this problem. In this study, we present an approach for the efficient screening of canine antibodies targeting CPV using a single B cell antibody technique. We sorted single IgM- IgG+ CPV+ B cells from canine peripheral blood mononuclear cells using fluorescence-activated cell sorting (FACS) and obtained the variable region genes of heavy and light chains (VH and VL) by nested PCR amplification. Canine monoclonal antibodies were expressed in HEK293 cells, and a total of 60 antibodies were obtained, five of which demonstrated neutralizing activity against CPV. Those findings demonstrate the effectiveness of the method for obtaining canine monoclonal antibodies, which in turn aids in the identification and screening of neutralizing antibodies against various canine pathogens.

A significant proportion of the highly divergent and novel proteins of giant viruses are termed "hypothetical" due to the absence of detectable homologous sequences in the existing databases. The quality of genome and proteome annotations often relies on the identification of signature sequences and motifs in order to assign putative functions to the gene products. These annotations serve as the first set of information for researchers to develop workable hypotheses for further experimental research. The structure-function relationship of proteins suggests that proteins with similar functions may also exhibit similar folding patterns. Here, we report the first proteome-wide structure prediction of the giant Marseillevirus. We use AlphaFold-predicted structures and their comparative analysis with the experimental structures in the PDB database to preliminarily annotate the viral proteins. Our work highlights the conservation of structural folds in proteins with highly divergent sequences and reveals potentially paralogous relationships among them. We also provide evidence for gene duplication and fusion as contributing factors to giant viral genome expansion and evolution. With the easily accessible AlphaFold and other advanced bioinformatics tools for high-confidence de novo structure prediction, we propose a combined sequence and predicted-structure-based proteome annotation approach for the initial characterization of novel and complex organisms or viruses.