{"title":"First report of West Nile virus infections in horses in Tunisia from 2018 to 2023.","authors":"Chaima Badr, Mariem Handous, Jihene Nsiri, Imen ElBehi, Marwa Arbi, Abderrazak Maaroufi, Mohamed Ali Bennour, Raja Ben Osman, Khalil Dachraoui, Mondher Abbes, Anis Mahmoudi, Ines Khosrof, Soufiene Abrougui, Jihene Lachheb, Elyes Zhioua, Imen Larbi","doi":"10.1186/s12985-025-02918-0","DOIUrl":"10.1186/s12985-025-02918-0","url":null,"abstract":"<p><strong>Background: </strong>West Nile virus (WNV) is an arthropod borne virus, the most widely distributed of the encephalitic Orthoflaviviruses. It can cause severe neurological symptoms in both humans and horses. It poses an emerging threat to both public and animal health. In this study, we retrospectively screened 25 suspected WNV samples collected from 2018 to 2023.</p><p><strong>Materials and methods: </strong>A total number of 25 samples (brain tissue and blood) were collected from clinically affected horses and those already deceased across several locations in Tunisia. All samples were tested for the presence of WNV NS2A gene using qRT-PCR. Eleven positive samples underwent virus isolation in Vero cells and partial sequencing of their envelope (E) glycoprotein gene. The resulting sequences were analyzed to gain molecular and phylogenetic insights.</p><p><strong>Results: </strong>Eleven of the 25 (44%) samples were WNV positive and 11 partial E protein sequences were taken. The phylogenetic analysis revealed that all Tunisian isolates belonged to lineage 1a and were closely related to each other and formed a distinct group within the Mediterranean subtype of clade 1a. Tunisian WNV were characterized by the presence of a potential N-linked glycosylation site at residue 154-156 (Asn-Tyr-Ser) (NYS) and did not have the mutation E-I159V or E-I159A.</p><p><strong>Conclusion: </strong>Genomic monitoring of horses has revealed the circulation of WNV in several regions of Tunisia. Our findings highlight the critical need for prompt investigation of WNV infections in horses, as these cases may precede outbreaks of human cases in the country.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"318"},"PeriodicalIF":4.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12486666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145207916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Virology JournalPub Date : 2025-09-30DOI: 10.1186/s12985-025-02958-6
Xue Li, Pei Liu, Zhaohui Wang, Xuefei Wei, Shuai Gao, YuChen Fan, Huihui Liu, Kai Wang
{"title":"Correction: The value of promoter methylation of fibroblast factor 21 (FGF21) in predicting the course of chronic hepatitis B and the occurrence of oxidative stress.","authors":"Xue Li, Pei Liu, Zhaohui Wang, Xuefei Wei, Shuai Gao, YuChen Fan, Huihui Liu, Kai Wang","doi":"10.1186/s12985-025-02958-6","DOIUrl":"10.1186/s12985-025-02958-6","url":null,"abstract":"","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"314"},"PeriodicalIF":4.0,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12486573/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145201676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"From monolayer to spheroid: assessing influenza a virus infection in 2D and 3D cell culture of A549 and HEK293.","authors":"Hadiseh Shokouhi, Fatemeh Gholizadeh, Hosnieh Sokhandan, Mahsa Mollapour Sisakht, Parvaneh Mehrbod","doi":"10.1186/s12985-025-02939-9","DOIUrl":"10.1186/s12985-025-02939-9","url":null,"abstract":"<p><strong>Background and aim: </strong>Three-dimensional (3D) culture models better mimic cell-to-cell interactions compared to traditional two-dimensional (2D) cultures, providing more physiologically relevant alternative for virus infection studies. This study aimed to explore the effectiveness of 3D culture models for studying viral propagation using A549 and HEK293 cell lines in spheroid form with two different matrices: alginate (Alg) and a combination of alginate with methylcellulose (Alg + MC).</p><p><strong>Methods: </strong>The 3D cultures of A549 and HEK293 cells were generated in 2 matrices. The cultures were characterized by proliferation assay and size assessment. The matrices were further analyzed by scanning electron microscopy (SEM) and immunofluorescence microscopy. Influenza A virus/PR/8/34 (H1N1) was propagated in MDCK cell and virus infectious dose was determined. A549 and HEK293 cells were grown in 2D form and virus was adapted to these 2 cell lines in serial passages. The best yields were inoculated to 2D and 3D forms. The supernatants and cells were collected in 48 h and subjected to qPCR to determine and compare the virus propagation in 2D and 3D formats.</p><p><strong>Results: </strong>Spheroids derived from A549 and HEK293 cell lines were successfully developed in 2 different matrices and characterization confirmed assembly of the cells together with considerable growth rate and viability. In case of HEK293, in dissolved patterns, external supernatant of Alg + MC and in undissolved ones, external supernatant in Alg and external and internal supernatants in Alg + MC showed the lowest decrement in viral load. Regarding A549, among dissolved ones, internal supernatants in Alg and Alg + MC and in undissolved samples, external and internal supernatants in Alg and internal supernatants in Alg + MC showed the least reduction. In both cell samples reduction was observed in all matrices, which was significant in A549 cell (P<0.05).</p><p><strong>Conclusion: </strong>We conclude that Alg + MC matrix, with its increased porosity and lower cohesion compared to Alg alone, was easier to dissolve but more difficult to re-solidify. One possible explanation for the observed higher viral replication in this matrix is that it may have facilitated improved viral access to the cells. Future modifications that increase virus-cell interaction time in this system could further enhance infection efficiency.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"309"},"PeriodicalIF":4.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12481871/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145192993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Virology JournalPub Date : 2025-09-29DOI: 10.1186/s12985-025-02947-9
Kang Zhou, Shuang Wu, Yunhui He, Rui Zhou, Wen Zhang, Can Xu, Zhimin Tang
{"title":"Molecular characterization of four novel mycoviruses in entomopathogenic and nematophagous fungi.","authors":"Kang Zhou, Shuang Wu, Yunhui He, Rui Zhou, Wen Zhang, Can Xu, Zhimin Tang","doi":"10.1186/s12985-025-02947-9","DOIUrl":"10.1186/s12985-025-02947-9","url":null,"abstract":"<p><strong>Background: </strong>Research on fungal viruses has predominantly focused on phytopathogenic fungi, with some studies elucidating their roles in modulating fungal virulence and influencing plant-fungus interactions. In contrast, mycoviruses harbored by entomopathogenic and nematophagous fungi have received significantly less attention.</p><p><strong>Methods: </strong>Eleven transcriptome datasets were de novo assembled and annotated using Diamond against the NCBI non-redundant protein database. Viral sequences, potential open reading frames (ORFs), and deduced amino acid sequences were analyzed using DNAMAN. Phylogenetic analysis was conducted based on the amino acid sequences.</p><p><strong>Results: </strong>This study characterized four mycoviruses from Hirsutella satumaensis, Ophiocordyceps sinensis, and Orbilia oligospora. Based on BLASTp analysis, the amino acid sequences of these viral genomes showed 50% to 98% identity to those of known viruses. Detailed sequence analysis revealed that Hirsutella satumaensis botourmiavirus 1 (HsBV1), Ophiocordyceps sinensis mitovirus 4 (OsMV4), Orbilia oligospora negative-strand RNA virus 1 (OoNSV1), and Orbilia oligospora narnavirus 1 (OoNV1) contained nearly complete genomes. Each virus featured a single open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) with a conserved GDD motif. Additionally, their variable 3' untranslated regions (3'-UTRs) and 5'-UTRs were predicted to form stable stem-loop secondary structures, which may play roles in viral replication or stability. Phylogenetic analysis indicated that these mycoviruses belong to the families Aspiviridae, Botourmiaviridae, Mitoviridae, and Narnaviridae.</p><p><strong>Conclusions: </strong>These findings expand our understanding of mycoviral diversity in nematophagous and entomopathogenic fungi. Further research is needed to explore whether these mycoviruses influence fungal interactions with insects or nematodes, which may uncover novel ecological and functional roles.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"313"},"PeriodicalIF":4.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12482373/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145192984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Risk of HBV transmission from HBcAb-positive grafts in pediatric liver transplantation: a real-world prospective cohort study.","authors":"Yuting Yang, Guojin Wu, Xiaoke Dai, Tengteng Zhang, Bingqian Tan, Yue Lu, Mingman Zhang, Yao Zhao","doi":"10.1186/s12985-025-02941-1","DOIUrl":"10.1186/s12985-025-02941-1","url":null,"abstract":"<p><strong>Background: </strong>The utilization of liver grafts from hepatitis B core antibody (HBcAb)-positive donors is relatively common in regions with high hepatitis B virus (HBV) prevalence. This practice poses a potential risk of HBV transmission. However, the impact of these grafts on pediatric liver transplant recipients is not well-established.</p><p><strong>Method: </strong>To address these knowledge gaps, we conducted a prospective observational cohort study to assess the risk of post-transplant HBV transmission in pediatric recipients of HBcAb-positive grafts. Hepatitis B serology and liver tissue analyses for HBV DNA were performed during post-transplantation follow-up of 188 pediatric recipients.</p><p><strong>Results: </strong>In the cohort study, 43 pediatric recipients (22.9%) received HBcAb-positive grafts, while 145 (77.1%) received HBcAb-negative grafts. Over a median follow-up of 43 weeks, 10 recipients (5.3% of the total cohort) developed HBV infection. The cumulative incidence of de novo HBV infection was significantly higher in recipients of HBcAb-positive grafts (18%, 95% CI: 5-31) compared to recipients of HBcAb-negative grafts (3%, 95% CI: 0-6, p < 0.05). Notably, higher levels of hepatitis B surface antibody (HBsAb ≥ 100mIU/ml) in pediatric recipients were associated with a significantly reduced risk of post-transplant de novo HBV infection (p < 0.05).</p><p><strong>Conclusion: </strong>HBcAb-positive grafts substantially increase HBV transmission risk in pediatric liver transplantation. Elevated HBsAb titers may mitigate infection severity, while occult HBV infections require vigilant monitoring. Strategic enhancement of recipient HBsAb levels and optimized prophylactic protocols are critical for improving outcomes.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"312"},"PeriodicalIF":4.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12482531/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145192988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of a single-tube, dual-target CRISPR Cas12a/Cas13a system for rapid screening of coinfection with respiratory syncytial virus and rhinovirus.","authors":"Xin-Yi Zhao, Chang Gao, Wen-Wu Zhao, Zi-Han Zhou, Tian-Chi Zhuang, Cheng Guo, Ming-Hui Ji","doi":"10.1186/s12985-025-02938-w","DOIUrl":"10.1186/s12985-025-02938-w","url":null,"abstract":"<p><strong>Background: </strong>Respiratory syncytial virus (RSV) and human rhinovirus (HRV) are leading causes of respiratory infections in children, with increasing reports of coinfections leading to severe complications. Current CRISPR-based detection systems, such as Cas12a and Cas13a, are limited in multiplex detection due to the lack of specific reporter cleavage mechanisms. This study aims to develop a rapid, sensitive, and single-tube dual-gene detection method for RSV and HRV using the orthogonal trans-cleavage activities of CRISPR-Cas12a/13a combined with reverse transcription-recombinase polymerase amplification (RT-RPA).</p><p><strong>Methods: </strong>We designed a novel detection system leveraging RT-RPA for amplification and the distinct cleavage activities of Cas12a and Cas13a for simultaneous dual-gene detection.</p><p><strong>Results: </strong>The reaction components were optimized to complete detection within 30 min, achieving sensitivities of 10 copies/µL for RSV and 10<sup>2</sup> copies/µL for HRV. Clinical validation was performed on 543 respiratory infection samples, confirming high accuracy and specificity.</p><p><strong>Conclusions: </strong>The RT-RPA-CRISPR-Cas12a/13a system provides a rapid, sensitive, and efficient solution for RSV and HRV coinfection detection. This method supports early diagnosis and improved clinical management, offering significant potential for public health applications in preventing severe respiratory complications in children.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"311"},"PeriodicalIF":4.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12482678/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145193027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Epidemiology and genetic diversity of norovirus GII genogroups among pediatric patients in Beijing, China, during 2023-2024.","authors":"Junhong Ai, Qiliang Li, Ke Xu, Yuxuan Li, Ying Liu, Luci Huang, Wenqi Song, Zhengde Xie","doi":"10.1186/s12985-025-02927-z","DOIUrl":"10.1186/s12985-025-02927-z","url":null,"abstract":"<p><strong>Background: </strong>Norovirus is an important cause of viral acute gastroenteritis (AGE) worldwide.</p><p><strong>Methods: </strong>In order to characterize the molecular epidemiology and genetic diversity of norovirus in children in Beijing, 3634 anal swab samples of AGE patients from January 2023 to December 2024 were analyzed. Norovirus was detected using RT-PCR and genotyped by sequencing the partial RdRp and VP1 region.</p><p><strong>Results: </strong>During the two-year period, norovirus was detected in 19.6% of AGE cases, with the highest detection rate in children under 3 years of age. GII.4 and GII.P16 were the dominant genotypes of VP1 and RdRp, with a detection rate of 36.39% and 44.59%, respectively. According to the dual-typing system combined the RdRp and VP1, the dominant genotypes of norovirus changed between 2023 and 2024. In 2023, the most common genotype was GII.3[P12] (39.15%), followed by GII.4 Sydney[P16] (32.34%) and GII.4 Sydney[P31] (15.32%). However, in 2024, the dominant genotype was GII.17[P17] (41.43%), followed by GII.4 Sydney[P16] (34.29%) and GII.3[P12] (20.0%). The GII.17 variants in this study were divided into two clusters: cluster IIIa and IIIb, which shared high nucleotide identity with GII.17 variant emerged in 2014/2015. Significantly, GII.4 Sydney[P31] and novel GII.4 Sydney[P16] variants co-circulating in this region from 2023 to 2024.</p><p><strong>Conclusion: </strong>The data provided useful information on the molecular epidemiology of norovirus in sporadic AGE among children and highlighted the necessary to continuously monitor the epidemiological characteristics of norovirus associated AGE.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"310"},"PeriodicalIF":4.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12482263/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145193033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Virology JournalPub Date : 2025-09-29DOI: 10.1186/s12985-025-02935-z
Arthur Kruse Sørensen, Jeroen Wagemans, Md Sabuj Hosen, Hermoine Jean Venter, Jorunn Pauline Cavanagh, Klara Stensvåg, Rob Lavigne, Gabriel Magno de Freitas Almeida
{"title":"A link to the past: classical phage ISP infects the recently described Staphylococcus borealis species.","authors":"Arthur Kruse Sørensen, Jeroen Wagemans, Md Sabuj Hosen, Hermoine Jean Venter, Jorunn Pauline Cavanagh, Klara Stensvåg, Rob Lavigne, Gabriel Magno de Freitas Almeida","doi":"10.1186/s12985-025-02935-z","DOIUrl":"10.1186/s12985-025-02935-z","url":null,"abstract":"<p><strong>Background: </strong>Staphylococcal infections, caused by a large variety of species within the Staphylococcus genus, are a threat to human health. Although antibiotics are the current choice of treatment for these infections, bacteriophage (phage) therapy has been used with success against Staphylococcus since the dawn of phage therapy. In 2020 a new coagulase-negative species named Staphylococcus borealis was described in Norway. In this study, we focused on understanding phage infections in S. borealis.</p><p><strong>Methods: </strong>First, we predict the presence of prophages and phage-defence mechanisms in the genomes of a collection of twelve S. borealis strains by bioinformatics. We also attempted to isolate S. borealis-infecting phages from Norwegian samples and tested the host-range of three known staphylococcal phages against a panel of fifty Norwegian staphylococcal strains.</p><p><strong>Results: </strong>The presence of prophages and phage defence systems was verified in all tested S. borealis strains. No local Norwegian phages could be obtained in a phage isolation attempt targeted towards S. borealis. The host range analysis shows that phage ISP, originally isolated in the 1920s and still used for phage therapy to date, can infect S. capitis and the S. borealis Hus23 strain. Phage ISP was shown to limit S. borealis Hus23 growth in liquid cultures and lower the formation of biofilm by the bacterium. The efficiency of plating of phage ISP can be improved by repeated passages in the new S. borealis Hus23 host.</p><p><strong>Conclusions: </strong>here we expand the known host range of the traditional phage ISP by showing that it also infects S. borealis and can be adapted to the new host by serial passages, showcasing the flexibility of phages as an antimicrobial strategy.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"308"},"PeriodicalIF":4.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12482510/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145192899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Two distinct polymorphisms in the basic region of Meq protein of marek's disease virus alter pathological progression and clinical manifestations.","authors":"Jumpei Sato, Aoi Kurokawa, Yoshinosuke Motai, Shunsuke Yamagami, Shwe Yee Win, Fumiya Horio, Hikaru Saeki, Naoya Maekawa, Tomohiro Okagawa, Benedikt B Kaufer, Nikolaus Osterrieder, Mark S Parcells, Satoru Konnai, Kazuhiko Ohashi, Shiro Murata","doi":"10.1186/s12985-025-02930-4","DOIUrl":"10.1186/s12985-025-02930-4","url":null,"abstract":"<p><strong>Background: </strong>Marek's disease virus (MDV) causes Marek's disease (MD) in chickens, which is characterized by malignant lymphomas and neurological disorders. Although MD is currently controlled using live vaccines, the virulence of field strains has continuously increased in recent decades. Polymorphisms in the MDV-encoded oncoprotein Meq are shared among field strains according to their virulence. In particular, very virulent MDV strains harbor characteristic amino acid changes in the basic region of Meq at positions 77 and 80; however, the contribution of these polymorphisms to virulence remains unclear.</p><p><strong>Methods: </strong>To assess the impact of these polymorphisms on MDV virulence, we generated recombinant MDV (rMDV) based on the very virulent RB-1B strain, harboring K77E and D80Y substitutions in Meq found in low-virulent strains (rRB-1B_Meq77/80). Chickens were challenged with rMDVs, and survival rates and tumor incidence were evaluated. Viral loads in major organs were quantified by quantitative PCR, and the dynamics of MDV-infected cells and T cells were analyzed using flow cytometry. In addition, histopathological analysis was performed to further examine differences in pathogenesis in detail. To elucidate the mechanisms underlying pathogenesis, we conducted reporter assays to assess the effect of these polymorphisms in the basic region on its transcriptional regulatory activity.</p><p><strong>Results: </strong>rRB-1B_Meq77/80 exhibited a reduced virulence but unexpectedly caused other clinical signs, including open-mouth breathing, in infected chickens. Quantitative PCR analysis showed consistently lower viral loads across all examined organs in rRB-1B_Meq77/80-infected chickens. Flow cytometric analysis revealed a reduction in MDV-infected cells, accompanied by a notable increase in CD8⁺ T cell populations. Histopathological analysis showed bronchus-associated lymphoid tissue hyperplasia in the lungs. Reporter assays revealed that most amino acid substitutions in the basic region in low-virulence strains reduced transcriptional regulatory activity.</p><p><strong>Conclusion: </strong>Our data indicate that polymorphisms at positions 77 and 80 in the Meq of low-virulence strains reduce MDV virulence and Meq-mediated transcription and possibly alter pathogenesis. This study improves our understanding of the mechanisms underlying MDV virulence.</p>","PeriodicalId":23616,"journal":{"name":"Virology Journal","volume":"22 1","pages":"303"},"PeriodicalIF":4.0,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12466078/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}