Two novel poleroviruses were repeatedly identified by metagenomics in French barley over the 2018-2023 period. One showed ~ 98.5% nucleotide (nt) identity with plant-associated polerovirus 3 (PaPV3) identified by metagen...Two novel poleroviruses were repeatedly identified by metagenomics in French barley over the 2018-2023 period. One showed ~ 98.5% nucleotide (nt) identity with plant-associated polerovirus 3 (PaPV3) identified by metagenomics in Slovenia, while the second represents a novel species for which the name barley virus H (BVH) is proposed. Both viruses show a typical polerovirus genome organization but do not have ORF6 or ORF7. In French cereals samples, the most prevalent polerovirus was barley virus G (6.4%) followed by BVH (2.3%), cereal yellow dwarf virus RPV (CYDV-RPV, 1.8%) and PaPV3 (0.9%) suggesting the novel poleroviruses to be as prevalent as CYDV.
Grapevine red blotch disease (GRBD) poses a serious threat to viticulture in the United States. Grapevine red blotch virus (GRBV), a member species of Grablovirus vitis (family Geminiviridae), the causal agent of GRBD, d...Grapevine red blotch disease (GRBD) poses a serious threat to viticulture in the United States. Grapevine red blotch virus (GRBV), a member species of Grablovirus vitis (family Geminiviridae), the causal agent of GRBD, disrupts grapevine physiology and metabolism, thereby interfering with the natural processes of fruit ripening. To date, there is limited knowledge about how grape maturity stages influence the timing of changes in viral load and disease progression. This study elucidates the effect of fruit maturity stages on GRBV accumulation in Vitis vinifera L. cv. Merlot grapevines in a Central Coast vineyard in California. Petioles from six basal leaves at random from previously GRBV-infected vines were collected at pre-véraison, véraison, post-véraison, and harvest stages, across two years (2021 and 2022). The viral copy number was quantified using digital PCR. The study identified significant differences (p < 0.05) in GRBV copy number across different maturity stages in 2021, irrespective of the year of infection. The lowest viral load was observed during the pre-véraison stage, and the highest at harvest, indicating progressive viral accumulation as the grapevines development progressed. In 2022, however, no significant difference in viral load across maturity stages was detected, an outcome attributed to extreme heat spikes coinciding with sampling periods. Our findings highlight the interplay between GRBV accumulation, grape development, and environmental parameters.
Epstein-Barr virus (EBV) is a complex human herpesvirus characterized by a protein core, a 162-capsomer nucleocapsid, and a glycoprotein-spiked envelope, which facilitates its transmission through bodily fluids. The viru...Epstein-Barr virus (EBV) is a complex human herpesvirus characterized by a protein core, a 162-capsomer nucleocapsid, and a glycoprotein-spiked envelope, which facilitates its transmission through bodily fluids. The virus primarily targets B cells and oropharyngeal epithelial cells, establishing infection through viral gp350/220 binds to the host CD21/CR2 receptor, followed by gp42 interacting with HLA class II molecules to trigger endocytosis. Once infection is established, EBV utilizes two main types of encoded microRNAs to regulate the host environment. The BHRF1 miRNAs are expressed early to promote rapid cell proliferation and prevent B-lymphocyte apoptosis by targeting pro-apoptotic proteins. Meanwhile, the BART miRNA cluster, including miR-BART1, miR-BART2, miR-BART3, miR-BART4, miR-BART7, miR-BART8, and miR-BART22, which are robustly expressed in epithelial malignancies like nasopharyngeal and gastric carcinomas, has been found to significantly suppress caspase-3, a central executioner of apoptosis and target host immune mediators like CXCL-11 to stifle antiviral responses. Moreover, Min et al. discovered that miR-BART1-3p inhibited the expression of Disabled homolog 2 (DAB2), a tumor suppressor gene linked to apoptosis, in EBVaGC cells, allowing them to evade programmed cell death. EBV's ability to cycle between B cells and epithelial cells, along with its association with the modulation of host cell processes and immune responses, highlights the mechanisms by which EBV establishes infection and contributes to oncogenesis.
A novel virus belonging to the genus Marafivirus was identified from the male Oriental persimmon (Diospyros kaki Thunb.) cultivar 'Kumemaru'. The complete genome of persimmon marafivirus (PerMaV) is 6,397 nucleotides in...A novel virus belonging to the genus Marafivirus was identified from the male Oriental persimmon (Diospyros kaki Thunb.) cultivar 'Kumemaru'. The complete genome of persimmon marafivirus (PerMaV) is 6,397 nucleotides in length and encodes a single large polyprotein containing conserved domains typical of viruses in the genus Marafivirus. Phylogenetic and sequence identity analyses indicate that PerMaV represents a new species in the family Tymoviridae.
Metatranscriptomic analysis of Wyeomyia confusa mosquitoes collected in the Atlantic Forest (Pindamonhangaba, São Paulo, Brazil) led to the identification of a previously uncharacterized virus, designated Wyeomyia confus...Metatranscriptomic analysis of Wyeomyia confusa mosquitoes collected in the Atlantic Forest (Pindamonhangaba, São Paulo, Brazil) led to the identification of a previously uncharacterized virus, designated Wyeomyia confusa Lispivirus (WcLispV-SP), classified within the family Lispiviridae, genus Canmovirus. The viral genome consists of a negative-sense single-stranded RNA (ssRNA-) of 12,698 nucleotides, encoding six open reading frames (ORFs): nucleoprotein (N), two hypothetical proteins (HP/1 and HP/2), glycoprotein (G), ORFan protein, and RNA-dependent RNA polymerase (RdRp-L). Phylogenetic analysis supports the classification of WcLispV-SP as a distinct species within the genus Canmovirus. Structural analysis of the RdRp revealed conserved domains and catalytic motifs characteristic of members of the order Mononegavirales, supporting its functional integrity. These findings expand the known diversity of the Lispiviridae family and highlight the utility of metagenomic approaches for the discovery and characterization of RNA viruses associated with Neotropical sylvatic mosquitoes.
Adenoviruses are the pathogens of a widespread adenovirus disease that affect wide range of hosts. 100 K protein is an important scaffolding protein for hexon assembly of the adenovirus. In recent years, the 100 K in the...Adenoviruses are the pathogens of a widespread adenovirus disease that affect wide range of hosts. 100 K protein is an important scaffolding protein for hexon assembly of the adenovirus. In recent years, the 100 K in the adenovirus attract more attention. Therefore, the character, location, and function of the 100 K protein is summarized from the past ten years. The current 100 K research mainly focuses on hexon assembly. The role of 100 K protein in hexon assembly is illustrated in detail. At early and late stages of hexon assembly, 100 K protein has localized to the nucleus and the cytoplasm to exert different functions. Its role in human granzyme B (GrB) and viral mRNA translation are also very important but have received little attention. The suppression of GrB by 100 K promote viral mRNA translation through inhibiting cell apoptosis. 100 K protein promotes hexon assembly through inhibition of cellular mRNA translation and cell apoptosis. The 100 K protein in ELISA kit may be used in differentiation of infected chickens from FAdV vaccinated chickens, but that in the vaccine has little capacity to protect adenovirus infection. Meanwhile, the adenovirus vector with 100 K protein will hold promise for diverse gene therapy applications. This review will facilitate a better understanding of 100 K protein function during adenovirus infection.
Vaccinia virus (VACV) is a member of the Poxviridae family and served as the vaccine strain used to eradicate smallpox. As a large double-stranded DNA virus, VACV exhibits a broad host range and remains a model organism...Vaccinia virus (VACV) is a member of the Poxviridae family and served as the vaccine strain used to eradicate smallpox. As a large double-stranded DNA virus, VACV exhibits a broad host range and remains a model organism for studying viral evolution and gene expression. Codon usage bias (CUB) is a fundamental feature of genome evolution that reflects the interplay between mutational pressure and natural selection. In this study, we systematically analyzed codon usage patterns in 107 strains of Vaccinia virus (VACV) to uncover the driving forces behind its genomic evolution and host adaptation. Our findings revealed a strong A/T bias across all codon positions, particularly at the third codon position (AT3 = 66.59%), suggesting a mutational or selective preference for A/T-ending codons. RSCU analysis confirmed the predominance of A/T-ending codons, while dinucleotide abundance showed balanced usage without significant suppression, unlike host genomes such as Homo sapiens and Bos taurus. CAI and RCDI analyses demonstrated that VACV codon usage is better adapted to Homo sapiens, highlighting potential host-specific evolutionary pressures. The PR2 and neutrality plots further emphasized the dominant role of natural selection, with minor contributions from mutational bias. Correspondence analysis indicated that geographic origin had limited influence on codon usage variation, while correlation and ENC-GC3s analyses reinforced the interplay between mutational pressure and selection. Phylogenetic analysis revealed regional clustering of strains, particularly from Brazil and the USA, indicating localized viral evolution. Overall, our results suggest that natural selection is the primary force shaping VACV codon usage, facilitating its efficient replication and adaptation across host environments.
The aim of this study was to evaluate the diagnostic potential of human papillomavirus type 18 (HPV18) E6/E7-specific T cell receptor (TCR)-like antibodies for the early detection of HPV-associated cervical cancer. An in...The aim of this study was to evaluate the diagnostic potential of human papillomavirus type 18 (HPV18) E6/E7-specific T cell receptor (TCR)-like antibodies for the early detection of HPV-associated cervical cancer. An integrated in silico and in vitro approach was employed, in which three fully human TCR-like antibodies (H11\Ab, E5\Ab, and G8\Ab) were analysed by molecular docking to assess antibody-peptide-major histocompatibility complex (P-MHC) class I HLA-A24:02 interactions, followed by experimental validation using SiHa and C33A cervical cancer cell lines. Docking analyses demonstrated stable, high-affinity interactions between the antibodies and their corresponding peptide-MHC complexes, consistent with experimental observations. In vitro assays confirmed strong binding specificity and functional activity in HPV18-positive cells, with no detectable reactivity in HPV-negative controls. These findings demonstrate that TCR-like antibodies targeting HPV18 E6/E7 peptide-MHC complexes enable highly specific detection of HPV-associated cervical cancer and support their potential application as early diagnostic biomarkers.
Occult hepatitis B virus Infection (OBI) is a form of hepatitis B virus (HBV) persistence that is not accompanied by the presence of circulating HBsAg. It is generally defined as the presence of replication-competent vir...Occult hepatitis B virus Infection (OBI) is a form of hepatitis B virus (HBV) persistence that is not accompanied by the presence of circulating HBsAg. It is generally defined as the presence of replication-competent viral DNA, mostly covalently closed circular DNA (cccDNA), in hepatocytes. Although viral load is low and serum markers are typically undetectable, OBI has clinical significance due to its association with transmission, reactivation under immunosuppression, HCV replicative levels, and the progression of liver fibrosis, cirrhosis, and hepatocellular carcinoma. The presence of cccDNA, a stable episomal minichromosome sustained through epigenetic regulation and immune evasion mechanisms, forms the basis for viral evasion of immune clearance and diagnostic detection. The molecular drivers of OBI involve complex interactions among three key factors: viral genetic mutations (particularly in the S region), epigenetic modifications (including cytosine methylation and histone modifications), and host immune responses that are often weakened or exhausted. This review integrates current knowledge regarding these molecular pathways and their contributions to OBI's persistence, reactivation, and associated diseases. A comprehensive understanding of these mechanisms is essential for improving diagnostic approaches, developing targeted therapies, and ultimately achieving the eradication of HBV in this resistant form of infection.
Viral vectors have emerged as powerful platforms for producing medical and metabolite products. To explore how diverse regulatory components can enhance gene expression, and leveraging the abundant diversity of long inte...Viral vectors have emerged as powerful platforms for producing medical and metabolite products. To explore how diverse regulatory components can enhance gene expression, and leveraging the abundant diversity of long intergenic regions (LIRs) in geminiviruses, we systematically screened the bidirectional promoter activities of 209 LIR fragments from 8 genera within the Geminiviridae family. This screening was performed using a dual-reporter vector (GFP/Firefly luciferase) via transient expression in Nicotiana benthamiana, leading to the identification of four highly active LIR elements (LIR-2, 37, 51, and 62) derived from three distinct genera. Corresponding geminivirus expression vectors were then constructed based on these LIRs. Among them, the GM2, GM37, and GM62 vectors significantly enhanced GFP/GUS expression levels, showing 1.27 ± 0.20- to 1.82 ± 0.17-fold and 1.16 ± 0.10- to 1.64 ± 0.33-fold increases at 3 dpi, respectively, compared to the cauliflower mosaic virus 35S promoter in the pCAMBIA1300 plant vector. Furthermore, these vectors successfully expressed the medically relevant protein human papillomavirus 16 L1 (HPV16 L1), which is typically difficult to express using the pCAMBIA1300 vector. The GM2 vector exhibited the highest expression level, reaching 1.70 ± 0.38 times that of GM37, underscoring its potential as a superior expression platform. Collectively, the LIR elements identified in this study enrich the toolbox for developing virus-based expression vectors in plants, and are particularly suitable for applications in plant bioreactors requiring simultaneous expression of multiple target molecules.
de Araújo CS, Henrique LGA, da Silva Oliveira HG
… +11 more, da Rocha JHL, de Souza JD, de Souza Lima A, Ribeiro VMF, da Silva FC, Driemeier D, Canal CW, Munday J, Salvarani FM, da Silva FRC, Daudt C
Wild rodents remain underrepresented in papillomavirus genomics, limiting current understanding of host range, tissue tropism, and evolutionary diversity. Here, we report the first papillomavirus identified in the spotte...Wild rodents remain underrepresented in papillomavirus genomics, limiting current understanding of host range, tissue tropism, and evolutionary diversity. Here, we report the first papillomavirus identified in the spotted lowland paca, Cuniculus paca, from the Brazilian Amazon, provisionally designated Cuniculus paca papillomavirus 1 (CpPV1). Histopathological examination supported the diagnosis of a virally induced squamous papilloma. Broad-range L1 PCR (FAP59/64), rolling-circle amplification, and Illumina MiSeq sequencing enabled recovery of a complete circular genome of 8,803 bp containing the canonical early (E6, E7, E1, and E2) and late (L2 and L1) open reading frames, together with a typical long control region. Pairwise comparison of the complete L1 gene showed 63.10% nucleotide identity to Erethizon dorsatum papillomavirus 2 (EdPV2), well below the threshold used for papillomavirus type demarcation. Maximum-likelihood phylogenetic analysis recovered CpPV1 as a distinct lineage sister to EdPV2 within a broader, non-monophyletic rodent papillomavirus assemblage. This finding expands the known diversity of Papillomaviridae in Neotropical rodents and provides new insight into papillomavirus evolution in an under-sampled host group.
Fusarium root rot, a persistent soil-borne disease, poses a serious threat to crop production, quality, and ultimately to food security. We identified two double-stranded RNA viruses co-infecting the phytopathogenic fung...Fusarium root rot, a persistent soil-borne disease, poses a serious threat to crop production, quality, and ultimately to food security. We identified two double-stranded RNA viruses co-infecting the phytopathogenic fungus Fusarium oxysporum strain 3 S-18: Fusarium oxysporum partitivirus 1 isolate 3 S-18 (FoPV1/3S18) and Fusarium oxysporum virus 1 (FoV1). The genome of FoPV1/3S18 consists of two segments. dsRNA1 is 1,761 nt in length with a large open reading frame (ORF) encoding an RNA-dependent RNA polymerase (RdRp) of 539 amino acids (aa). dsRNA2 is 1,556 nt in length with an ORF encoding a putative coat protein (CP) of 430 aa. Phylogenetic analysis based on both RdRp and CP amino sequences indicated that FoPV1/3S18 clusters with the members of the genus Gammapartitivirus within the family Partitiviridae. FoV1 was identified as a new monopartite dsRNA virus with 2,944 nt, containing two ORFs which encode a protein of 590 aa RdRp and 134 aa nucleocapsid protein, respectively. It belongs to the genus Unirnavirus, family Amalgaviridae. Furthermore, we demonstrated that both FoPV1/3S18 and FoV1 can be successfully transmitted via hyphal anastomosis to a virus-free strain. Co-infection with FoV1 and FoPV1/3S18 reduced conidial production but did not attenuate fungal virulence. However, infection with FoV1 alone not only reduced conidial production but also induced hypovirulence.
Over the past three decades, cetacean morbilliviruses (CeMVs) have emerged as significant pathogens affecting cetacean populations worldwide. Here, we report the genome sequence of a new CeMV, designated Fraser's dolphin...Over the past three decades, cetacean morbilliviruses (CeMVs) have emerged as significant pathogens affecting cetacean populations worldwide. Here, we report the genome sequence of a new CeMV, designated Fraser's dolphin morbillivirus (FDMV), isolated from a stranded Fraser's dolphin (Lagenodelphis hosei) in Hawai'i in 2018. Next-generation sequencing facilitated recovery of the nearly complete FDMV genome (15,685 bp), and annotation indicated a genomic organization similar to that of other morbilliviruses, including six open reading frames. Genetic analysis of the FDMV RNA-dependent RNA polymerase gene sequence showed 87-89.6% nucleotide sequence identity compared with other CeMV strains. Phylogenetic analysis demonstrated that FDMV is a distinct member of the genus Morbillivirus, branching as the most basal member of the CeMV clade, which may represent a new species.
Avian leukosis virus subgroup J (ALV-J) remains a major threat to poultry health and production, particularly in indigenous chicken populations in China. In this study, a highly pathogenic ALV-J field strain, YN2021, was...Avian leukosis virus subgroup J (ALV-J) remains a major threat to poultry health and production, particularly in indigenous chicken populations in China. In this study, a highly pathogenic ALV-J field strain, YN2021, was first isolated from indigenous black-bone chickens in Yunnan Province, China, and its biological characteristics and pathogenicity were systematically evaluated in specific-pathogen-free (SPF) chickens. Infected chickens exhibited significant growth retardation, delayed sexual maturation, and increased mortality, accompanied by pathological lesions consistent with ALV-J. To further assess reproductive performance, egg production and egg weight were recorded. YN2021-infected hens showed a reduction in total egg production (70 vs. 92 eggs; ~23.9% decrease) and a significantly lower mean egg weight (35.2 ± 0.2 g vs. 43.7 ± 0.3 g; P < 0.001) compared to controls. To facilitate mechanistic studies and future control strategies, a full-length infectious clone of YN2021 was constructed using a reverse genetics approach, and a synonymous molecular marker was introduced for viral identification. The rescued recombinant virus exhibited replication kinetics, p27 antigen expression, and biological characteristics in DF-1 cells comparable to those of the parental strain, and the molecular marker remained genetically stable during serial passages. Collectively, these results demonstrate that the ALV-J YN2021 strain exhibits high pathogenicity and negatively affects growth and reproductive performance in chickens. The infectious clone established in this study provides a reliable experimental platform for investigating ALV-J pathogenesis and supports the development of effective control strategies to mitigate production losses in poultry.
We report the complete genome sequence of the bacteriophage vB_KaeP_KM5, which infects multidrug-resistant Klebsiella aerogenes and was isolated from hospital wastewater. The phage is classified within the class Caudovir...We report the complete genome sequence of the bacteriophage vB_KaeP_KM5, which infects multidrug-resistant Klebsiella aerogenes and was isolated from hospital wastewater. The phage is classified within the class Caudoviricetes, family Autotranscriptaviridae, and genus Teetrevirus.
Soybean stay-green associated virus (SoSGV) is an emerging begomovirus associated with severe disease in soybean crops in East Asia. This study investigated its evolutionary relationships, population structure, recombina...Soybean stay-green associated virus (SoSGV) is an emerging begomovirus associated with severe disease in soybean crops in East Asia. This study investigated its evolutionary relationships, population structure, recombination history, adaptive signal, and candidate host-interaction features using integrated phylogenetic, population genetic, natural selection, and structural modeling analyses of 54 complete genome sequences. Maximum-likelihood and Bayesian phylogenetic analyses recovered SoSGV as a distinct monophyletic lineage, with strong support in the maximum-likelihood analysis (96% bootstrap support). Population genetic analysis revealed high haplotype diversity (Hd = 0.962), moderate nucleotide diversity (π = 0.022), and a negative Tajima's D value (D = - 1.49, p < 0.05), a pattern consistent with recent demographic expansion but not, by itself, proof of emergence timing. Recombination screening identified two robust coat protein-associated events (best p = 1.95 × 10⁻⁷ and 1.91 × 10⁻¹⁴), and sliding-window similarity analysis independently supported the resulting mosaic structure. Natural selection analyses detected adaptive signal in the V2 gene; MEME identified episodic selection at residues 35 and 36 (p < 0.1), while complementary methods supported additional method-dependent signals. ColabFold predicted a moderate-confidence V2 structure (mean pLDDT = 73.36). Protein docking identified a plausible V2-SKP1-related interface comprising 39 contacting residues, while a short 10 ns molecular dynamics simulation indicated preliminary structural compatibility rather than biological validation. These findings support the hypothesis that recombination contributed to SoSGV diversification and that V2 may interact with SKP1-related host proteins.
Here, we present the complete genome sequence of a highly pathogenic fowl adenovirus serotype 4 (FAdV-4) isolate (PK-1-SBL2021), collected in 2021, from an infected chicken in Pakistan. Analysis of the genome sequence re...Here, we present the complete genome sequence of a highly pathogenic fowl adenovirus serotype 4 (FAdV-4) isolate (PK-1-SBL2021), collected in 2021, from an infected chicken in Pakistan. Analysis of the genome sequence revealed that PK-1-SBL2021 is closely related to highly pathogenic FAdV-4 isolates from neighboring countries (China and Iran). However, the genome is devoid of a large (1966 bp) deletion commonly found in highly pathogenic FAdV-4 isolates from neighboring countries (China and Iran). Other features of the genome, such as distinct amino acid substitutions in specific proteins encoded by the genome and repeat sequences, are similar to those found in highly pathogenic FAdV-4 isolates. To the best of our knowledge, PK-1-SBL2021 represents the first highly pathogenic FAdV-4 isolate identified in the region that lacks a 1966 bp deletion in its genome. Our sequence analysis reveals that the deletion is also lacking in the genomes of multiple pathogenic FAdV-4 isolates from Pakistan, suggesting that the genomic deletion is dispensable for increased virulence of FAdV-4.
Tomato spotted wilt virus (TSWV) is distributed all over Japan and globally, seriously damaging infected plants. A resistance-conferring gene, Tsw, that controls the yellow spotted wilt disease in bell pepper (Capsicum a...Tomato spotted wilt virus (TSWV) is distributed all over Japan and globally, seriously damaging infected plants. A resistance-conferring gene, Tsw, that controls the yellow spotted wilt disease in bell pepper (Capsicum annuum) plants caused by TSWV infection in Japan, is now commercially available. In this study, we isolated for the first time in Japan, a resistance-breaking isolate, TSWV-JRB, from bell pepper plants harboring Tsw. The virus overcame the resistance conferred by Tsw in its heterozygous and homozygous configurations. The host range or virulence of TSWV-JRB and one of the non-resistance breaking isolates from Japan did not differ, except in the plants harboring Tsw. The TSWV-JRB acquisition rates and transmission rates of the thrip pests Frankliniella occidentalis and F. intonsa were 93% 38%, and 78% and 38%, respectively. A phylogenetic analysis of the N gene sequences indicated a distant relationship between TSWV-JRB and other Japanese isolates but a close association with Asian and European isolates. A comparison of the amino acid sequences encoded by these resistance-breaking and non-resistance-breaking NSs suggested that a residue 74 (S→P) is a putative resistance breaking-associated substitution. This is the first study to report Tsw-induced resistance breaking by TSWV in Japan. These results indicated the presence of a novel substitution in TSWV that might contribute to Tsw-resistance breaking.
Porcine epidemic diarrhea virus (PEDV) G2c subtype has emerged as an increasingly prevalent variant causing widespread epidemic, high mortality and severe economic losses in the Chinese swine industry. The lack of specif...Porcine epidemic diarrhea virus (PEDV) G2c subtype has emerged as an increasingly prevalent variant causing widespread epidemic, high mortality and severe economic losses in the Chinese swine industry. The lack of specific and efficient detection methods hinders its surveillance, early detection and control. In this study, a TaqMan-MGB probe-based duplex quantitative real-time reverse transcription PCR (RT-qPCR) assay was developed for simultaneous detection of pan-PEDV and differentiation of the G2c subtype. Universal primers/probe targeting the conserved N gene of PEDV and G2c-specific primers/probe targeting the unique mutation sites in the S gene were designed. The assay was validated for performance, including specificity, sensitivity, and repeatability, and further evaluated using artificial challenge models and clinical samples. The standard curves exhibited excellent linearity (R > 0.999) with amplification efficiencies of 99.1% (Pan-pedv) and 98.4% (G2c). The limits of detection (LOD) were 10 copies/µL for Pan-pedv and 100 copies/µL for G2c subtype. No cross-reactivity was observed with 11 common swine diarrhea-related pathogens, and the G2c-specific channel exclusively recognized the G2c subtype. Intra-assay and inter-assay coefficients of variation (CVs) were < 1.40% and < 0.62%, respectively, confirming the good repeatability. In the artificial challenge model, the assay detected dynamic changes in fecal viral load consistent with the singleplex RT-qPCR. In clinical sample testing (n = 18), 13 PEDV-positive samples were identified, with 6 G2c-positive cases validated by Sanger sequencing. Collectively, this duplex RT-qPCR assay is sensitive, specific, and reliable, providing a valuable tool for rapid diagnosis, epidemiological surveillance, and targeted control of PEDV G2c subtype outbreaks.
A novel piscine adenovirus, Pagrus major adenovirus 1 (PmAdV-1), was identified in red seabream (Pagrus major) by metagenomic sequencing. The 29,519 bp genome encodes 22 predicted open reading frames and exhibits a uniqu...A novel piscine adenovirus, Pagrus major adenovirus 1 (PmAdV-1), was identified in red seabream (Pagrus major) by metagenomic sequencing. The 29,519 bp genome encodes 22 predicted open reading frames and exhibits a unique organization, with the fiber gene positioned upstream of the conserved adenovirus gene cluster. Phylogenetic analyses indicate that PmAdV-1 forms a sister lineage to red-eared slider adenovirus 1 within a clade of fish and reptilian adenoviruses, but its assignment to the genus Testadenovirus remains uncertain. A virus-specific qPCR assay was developed to monitor PmAdV-1 in environmental DNA from rearing seawater. Viral loads transiently increased in some juvenile tanks without marked mortality. These findings expand current knowledge of fish adenovirus diversity.