Viruses

16 pages, 2455 KB

Open AccessArticle

Prevalence and VP1 Gene Evaluation Analysis of Porcine Sapelovirus in Yunnan Province, China, from 2024 to 2025

by Zhanhong Li, Xuyu Tang, Zhenxing Zhang, Pei Zhu, Zhuoran Li, Peng Liu, Qi Yang, Li Meng, Xiutao Sun, Zhen Yang, Qiuyan Yang, Yifang Zhang and Jianling Song

Viruses 2025, 17(10), 1336; https://doi.org/10.3390/v17101336 - 30 Sep 2025

Abstract

Porcine Sapelovirus (PSV) is widely prevalent in pig herds throughout the world and induces diarrhea, encephalomyelitis, respiratory tract symptoms, and reproductive disorders. However, the epidemiological and genetic evolution characteristics of PSV remain unclear in Yunnan Province. In this study, 1622 fecal samples were [...] Read more.

Porcine Sapelovirus (PSV) is widely prevalent in pig herds throughout the world and induces diarrhea, encephalomyelitis, respiratory tract symptoms, and reproductive disorders. However, the epidemiological and genetic evolution characteristics of PSV remain unclear in Yunnan Province. In this study, 1622 fecal samples were collected from pig farms in Yunnan Province. PSV and its co-infection rates with other pathogens were detected; then, the PSV VP1 gene was amplified and sequenced; and the genetic evolution characteristics of the VP1 gene were analyzed. The overall infection rate of PSV in Yunnan Province was 36.50%, and the differences among regions were significant (p < 0.05). The positive rates among different seasons were significantly different (p < 0.01), ranging from 73.33% (autumn) to 19.00% (summer). The PSV positive rate in diarrhea samples (47.26%) was significantly higher (p < 0.001) than that of non-diarrhea samples (31.77%). The co-infection rates of PSV with porcine rotavirus (PoRV) and PSV with porcine epidemic diarrhea virus (PEDV) were 5.07% and 3.04%. A total of 36 VP1 sequences were obtained, and the average identity among the 36 sequences was 85.3%, which was higher than that with other reference strains. Phylogenetic analysis revealed that all 36 PSV strains belonged to the PSV-1 genotype. The VP1 gene was under strong negative selection pressure (average dN/dS = 0.0838); however, the 95th amino acid was under positive selection pressure. Our study revealed the epidemiological, co-infection, and genetic evolution characteristics of PSV in pig herds of Yunnan Province, providing more data for preventing and controlling diarrhea pathogens in pigs. Full article

(This article belongs to the Section Animal Viruses)

12 pages, 871 KB

Open AccessArticle

First Serological Evidence of Crimean-Congo Hemorrhagic Fever Virus Infections in Croatia: A Multispecies Surveillance Approach Emphasising the Role of Sentinel Hosts

by Gorana Miletic, Ivona Coric, Snjezana Kovac, Alenka Skrinjaric, Magda Kamber Taslaman, Margarita Bozikovic, Ljubo Barbic, Viktor Masovic, Jelena Prpic, Lorena Jemersic and Vladimir Stevanovic

Viruses 2025, 17(10), 1335; https://doi.org/10.3390/v17101335 - 30 Sep 2025

Abstract

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne zoonotic pathogen of growing public health concern in southeastern Europe. This study provides the first serological evidence of CCHFV circulation in Croatia, based on testing 1473 serum samples from farm and companion animals, including sheep, [...] Read more.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne zoonotic pathogen of growing public health concern in southeastern Europe. This study provides the first serological evidence of CCHFV circulation in Croatia, based on testing 1473 serum samples from farm and companion animals, including sheep, horses, cattle, goats, dogs, and cats. A total of 109 samples (7.4%) tested positive for CCHFV antibodies using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. The highest seroprevalence was recorded in sheep (28.3%), followed by horses (4.3%) and a single cat (0.5%), with no antibodies detected in cattle, goats, or dogs. Almost all seropositive animals originated from coastal and subcoastal Croatia, where Hyalomma ticks are present. Only two seropositive cases were detected in continental areas. Sheep samples from several farms in Zadar County showed intra-farm seropositivity rates of up to 85.7%, suggesting localised virus circulation likely influenced by vector distribution and farm-level practices. No viral ribonucleic acid (RNA) was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR), consistent with the transient nature of viremia in most animal hosts. These findings confirm the silent circulation of CCHFV in Croatia and reinforce the need for targeted, regionally adapted surveillance strategies that integrate multiple hosts and support early warning systems aligned with the One Health concept. Full article

(This article belongs to the Special Issue Emerging and Re-Emerging Viral Zoonoses)

► Show Figures

Figure 1

26 pages, 3861 KB

Open AccessArticle

Metagenomics Study of the Commercial Tomato Virome Focused on Virus Species of Epidemiological Interest

by Zafeiro Zisi, Isabel Ruiz Movilla, Nikolas Basler, Lila Close, Lucas Ghijselings, Robby Van der Hoeven, Maria Ioanna Papadaki, Ester Rabbinowitsch, Fiona Van Reeth, Jill Swinnen, Elise Vogel, Christine Vos, Inge Hanssen and Jelle Matthijnssens

Viruses 2025, 17(10), 1334; https://doi.org/10.3390/v17101334 - 30 Sep 2025

Abstract

Plant viruses have detrimental effects on commercial tomato cultivation leading to severe economic consequences. Viral metagenomics studies provide the opportunity to examine in depth the virome composition of a sample set without any pre-existing knowledge of the viral species that are present. In [...] Read more.

Plant viruses have detrimental effects on commercial tomato cultivation leading to severe economic consequences. Viral metagenomics studies provide the opportunity to examine in depth the virome composition of a sample set without any pre-existing knowledge of the viral species that are present. In the present study, 101 plant samples were collected from commercial greenhouses in 13 countries in Europe, Africa, Asia, and North America between 2017 and 2024. All samples were processed with the VLP enrichment protocol NetoVIR and the obtained data were analyzed with the ViPER pipeline. Forty-three eukaryotic viral species were identified, with a median identification of 2 species per sample. The most prevalent viral species were pepino mosaic virus (PepMV), tomato brown rugose fruit virus (ToBRFV), and southern tomato virus (STV). The obtained genome sequences were used to study the diversity and phylogeny of these viruses. The three genotypes identified for PepMV showed low diversity within each genotype (96.2–99.0% nucleotide identity). Low isolate diversity was also found for ToBRFV and STV. No significant association could be found between STV identification and the presence of symptoms, questioning the pathogenic potential of STV. Three other pathogenic viral species of particular interest due to their effects on tomato cultivation or recent emergence, namely tomato torrado virus (ToTV), tomato fruit blotch virus (ToFBV), and cucumber mosaic virus (CMV), were part of the virome with low prevalence. Our study provided a comprehensive overview of the analyzed samples’ virome, as well as the possibility to inspect the genetic diversity of the identified viral genomes and to look into their potential role in symptom development. Full article

(This article belongs to the Special Issue Advances in Plant Virus/Viroid Detection and Identification Methods)

► Show Figures

Figure 1

19 pages, 955 KB

Open AccessReview

HTLV-1 and ATLL: Epidemiology, Oncogenesis, and Opportunities for Community-Informed Research in the United States

by Adrian Altieri, Sean Patrick Reilly, Abu Mansalay, Alan Soo-Beng Khoo, Nettie Johnson, Zafar K. Khan, Amy Leader, Pooja Jain and Pierluigi Porcu

Viruses 2025, 17(10), 1333; https://doi.org/10.3390/v17101333 - 30 Sep 2025

Abstract

Human T-cell leukemia virus type 1 (HTLV-1), the first oncogenic human retrovirus, causes adult T-cell leukemia/lymphoma (ATLL), an aggressive neoplasm of mature CD4+ T-cells that is incurable in most patients and is associated with a median survival of less than 1 year. HTLV-1 [...] Read more.

Human T-cell leukemia virus type 1 (HTLV-1), the first oncogenic human retrovirus, causes adult T-cell leukemia/lymphoma (ATLL), an aggressive neoplasm of mature CD4+ T-cells that is incurable in most patients and is associated with a median survival of less than 1 year. HTLV-1 also causes inflammatory disorders, including HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and uveitis. The estimated lifetime risks of ATLL and HAM/TSP in HTLV-1 carriers are 3–5% and 0.25–1.8%, respectively. Although there is uncertainty about other health effects of HTLV-1, a recent meta-analysis showed an association between HTLV-1 and cardiovascular, cerebrovascular, and metabolic diseases and a 57% increased risk of early mortality in HTLV-1 carriers, independent of ATLL or HAM/TSP. Furthermore, emerging studies in endemic areas show that outcomes for common cancers, such as cervical cancer and lymphoma (non-ATLL), are inferior in HTLV-1 carriers compared to publicly reported data. Thus, the impact of HTLV-1 may be greater and more diverse than currently understood. This review provides an outline of the prevalence and impact of HTLV-1 and associated disorders in the US, focused on—but not limited to—ATLL, with an emphasis on the social determinants of health that can affect the success of screening and prevention strategies. We also discuss the mechanisms by which HTLV-1 drives the pathogenesis of ATLL and potential strategies for early diagnosis and intervention. Finally, we conclude by suggesting approaches to designing and implementing community-informed research initiatives in HTLV-1 and ATLL. Full article

(This article belongs to the Special Issue Human T-Cell Leukemia Virus (HTLV) Infection and Treatment: 2nd Edition)

► Show Figures

Figure 1

11 pages, 1033 KB

Open AccessBrief Report

The Antisense Protein ASP of HIV-1 Enhances Viral Entry in CD4+ T Cells

by Myriam Abla Houmey, Isabella Caico, Aurélie Rivault, Lucile Espert, Jean-Michel Mesnard, Fabio Romerio and Nathalie Chazal

Viruses 2025, 17(10), 1332; https://doi.org/10.3390/v17101332 - 30 Sep 2025

Abstract

The negative strand of the human immunodeficiency virus-1 (HIV-1) proviral genome contains an antisense open reading frame encoding a protein (ASP) with no known homologs. The presence of immune responses to ASP in people living with HIV-1 (PLWH) demonstrates its expression in vivo. [...] Read more.

The negative strand of the human immunodeficiency virus-1 (HIV-1) proviral genome contains an antisense open reading frame encoding a protein (ASP) with no known homologs. The presence of immune responses to ASP in people living with HIV-1 (PLWH) demonstrates its expression in vivo. Further, the predicted hydrophobicity of ASP is consistent with its association with the plasma membrane and viral envelope. Despite this body of evidence, the role of ASP in HIV-1 replication remains unknown. In this report, we investigated the hypothesis that the presence of ASP on the viral surface enhances HIV-1 entry into target cells. We generated an ASP-knockout replication-competent HIV-1 molecular clone in the NL4-3 background, which we used to perform cell–cell fusion, viral entry, and viral replication assays. Our results suggest that the presence of ASP on the plasma membrane of infected cells and the envelope of HIV-1 virions enhances viral transmission. Overall, our studies provide first evidence that ASP plays a role in the HIV-1 replication cycle. Further investigation into these observations may lead to the identification of new HIV-1 vulnerabilities that may be the target of novel interventions. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

► Show Figures

Figure 1

14 pages, 1774 KB

Open AccessArticle

Transcriptome Analysis Reveals Gemykibivirus Infection Induces Mitochondrial DNA Release in HEK293T Cells

by Runbo Yang, Hao Yan, Yifan Wang, Wenqing Yang and Jianru Qin

Viruses 2025, 17(10), 1331; https://doi.org/10.3390/v17101331 - 30 Sep 2025

Abstract

Gemykibivirus, an emerging single-stranded DNA (ssDNA) virus of the recently established genus in the family of Genomoviridae, had been discovered in human blood and cerebrospinal fluid and a variety of other body fluids. However, the molecular mechanisms of gemykibivirus entrance into the host [...] Read more.

Gemykibivirus, an emerging single-stranded DNA (ssDNA) virus of the recently established genus in the family of Genomoviridae, had been discovered in human blood and cerebrospinal fluid and a variety of other body fluids. However, the molecular mechanisms of gemykibivirus entrance into the host cells and its pathogenicity remain poorly understood. To investigate the host response of gemykibivirus, we used an infectious clone of gemykibivirus previously established through molecular biology techniques to rescue virus in HEK293T cells and analyzed the changes in the host transcriptome during the infection period by RNA-Seq. Our findings indicate that gemykibivirus can both express viral proteins and accomplish replication, and high-throughput transcriptome analysis identified a total 1732 significantly different genes. Functional enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for differentially expressed genes (DEGs) showed gemykibivirus involving several important pathways, including MAPK signaling pathway, Chemical carcinogenesis-reactive oxygen species and Oxidative phosphorylation. Interestingly, mitochondrial DNA-encoded mRNAs exhibited varying levels of upregulation, suggesting that gemykibivirus may be involved in mitochondrial fission and the regulation of mitochondrial function. Subsequently, a series of experiments proved that gemykibivirus can lead an increase in mitochondrial DNA copy number, promote the release of mtDNA into the cytoplasm, enhance reactive oxygen species production and trigger other cellular antiviral responses. Overall, we lay a foundation for revealing the relationship between Gemykibivirus and human diseases through mitochondrial functional alterations. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

► Show Figures

Figure 1

9 pages, 499 KB

Open AccessConference Report

Advancing Arbovirus Research in the Caribbean and Latin America: 2025 Global Virus Network Regional Meeting

by Tiffany R. Butterfield, Joshua J. Anzinger, John Lindo, Gene D. Morse, Sten H. Vermund and Maggie L. Bartlett

Viruses 2025, 17(10), 1330; https://doi.org/10.3390/v17101330 - 30 Sep 2025

Abstract

A May 2025 symposium convened leading virology experts across Latin America and the Caribbean (LAC) to advance regional research and collaborative efforts. Sessions explored cutting-edge developments in arbovirology, pressing challenges in viral surveillance, and the complexities of vector biology. Integrated networking opportunities and [...] Read more.

A May 2025 symposium convened leading virology experts across Latin America and the Caribbean (LAC) to advance regional research and collaborative efforts. Sessions explored cutting-edge developments in arbovirology, pressing challenges in viral surveillance, and the complexities of vector biology. Integrated networking opportunities and hands-on workshops offered mentorship and training, focused on the next generation of virologists, and strengthened scientific communication within the region. The morning session included reports from the LAC Global Virus Network (GVN) Centers of Excellence. A roundtable dialogue tackled the present challenges faced in arbovirus research. The Abbott Pandemic Defense Coalition reported on its collaborative progress. Trainees from the University at Buffalo, the State University of New York, and the University of the West Indies Global Infectious Diseases Research Training program showcased their current research projects. A session concentrated on health landscapes and the capacity for viral vaccinations within the region. A mentoring workshop focused on immune evasion methodologies and obstacles associated with arboviruses. One Health perspectives on viral zoonotic diseases addressed developments in the surveillance of vector-borne viruses in the Caribbean. Studies of mosquitoes and ticks as vectors of viruses included discussion on the neurovirulence of arboviruses and symptoms occurring after viral infections. Pediatric infectious diseases were highlighted in their environmental health context. An additional mentoring workshop centered on viruses and the microbiome. The relationship between viruses and cancer was discussed in the South American context and included recent advancements in the field of vaccinology. The Jamaica Regional GVN meeting promoted collaboration, facilitated the exchange of knowledge, and advanced research efforts throughout the region. Full article

(This article belongs to the Section General Virology)

► Show Figures

Figure 1

22 pages, 1471 KB

Open AccessArticle

Rift Valley Fever Virus Transmission During an Unreported Outbreak Among People and Livestock in South-Central Tanzania

by Robert D. Sumaye, Ana Pérola D. Brandão, Frank Chilanga, Goodluk Paul, Grace W. Mwangoka, Woutrina A. Smith, Abel B. Ekiri, Christopher Kilonzo, Solomon Mwakasungula, George Makingi, Amina A. Kinyogori, Walter S. Magesa, Aziza J. Samson, Catherine Mkindi, Peter Pazia, Feisal Hassan, Thabit A. Mbaga, Robinson H. Mdegela, Honorati Masanja, Deborah Cannon, Aridith Gibbons, John D. Klena, Joel M. Montgomery, Stuart T. Nichol, Lucija Jurisic, Alexandre Tremeau-Bravard, Hezron Nonga, Jamie Sebastian, Saba Zewdie, Leah Streb, Anna C. Fagre, Nicholas A. Bergren, Daniel A. Hartman, David J. Wolking, Rebekah C. Kading, Jonna A. K. Mazet and Brian H. Bird Show full author list Hide full author list

Viruses 2025, 17(10), 1329; https://doi.org/10.3390/v17101329 - 30 Sep 2025

Abstract

Rift Valley fever (RVF) is a re-emerging vector-borne zoonotic disease that causes outbreaks in humans and animals across Africa. To better understand RVF at human–animal interfaces, a prospective longitudinal survey of people, livestock, and mosquitoes was conducted from 2016 to 2018, in two [...] Read more.

Rift Valley fever (RVF) is a re-emerging vector-borne zoonotic disease that causes outbreaks in humans and animals across Africa. To better understand RVF at human–animal interfaces, a prospective longitudinal survey of people, livestock, and mosquitoes was conducted from 2016 to 2018, in two regions of Tanzania, with distinct climatic zones (Iringa and Morogoro). Molecular and serological tools for testing (RT-qPCR and IgM/IgG ELISA) for RVF virus (RVFV) were used to assess infection and exposure in people and animals. Mosquitoes were collected quarterly from 10 sentinel locations. In total, 1385 acutely febrile humans, 4449 livestock, and 3463 mosquito pools were tested. In humans, IgM seroprevalence was 3.75% (n = 52/1385), and overall seroprevalence (IgM and/or IgG positive) was 8.30% (n = 115/1385). People from Iringa had a higher exposure risk than those from Morogoro (aOR 2.63), and livestock owners had an increased risk compared to non-owners (aOR 2.51). In livestock, IgM seroprevalence was 1.09%, while overall seroprevalence was 10.11%. A total of 68.4% of herds had at least one seropositive animal. Sentinel animal follow-up revealed that the probability of seroconversion was significantly higher in Morogoro. Low-level RVFV RNA was detected in 8 human and 22 mosquito pools. These findings indicate active transmission among vectors, livestock, and people during the study period, highlighting the need for One Health surveillance approaches for RVFV and other arboviruses. Full article

(This article belongs to the Special Issue Rift Valley Fever Virus: New Insights into a One Health Archetype)

► Show Figures

Figure 1

2 pages, 133 KB

Open AccessCorrection

Correction: Lazov et al. Full-Genome Sequences of Alphacoronaviruses and Astroviruses from Myotis and Pipistrelle Bats in Denmark. Viruses 2021, 13, 1073

by Christina M. Lazov, Graham J. Belsham, Anette Bøtner and Thomas Bruun Rasmussen

Viruses 2025, 17(10), 1328; https://doi.org/10.3390/v17101328 - 30 Sep 2025

Abstract

Error in Table [...] Full article

10 pages, 2324 KB

Open AccessCase Report

Clade Ib Mpox in the Democratic Republic of the Congo (DRC): Clinical and Virological Report of the First Case in Kinshasa, the Capital City

by Franck Kasongo-Mulenda, Sylvie Lundi-Kizela, Sabrina Kalonji-Tshilomba, Deluxe Nsambayi-Lukusa, Mohesa Iteke, Richard Nkwembe-Mpileng, Abraham Muswibwe, Meris Matondo-Kuamfumu, Anguy Makaka, Junior Bulabula-Penge, Servet Kinbonza, Emile Malembi, Cris Kacita, Robert Shongo Lushima, Hélène Grace Otema-Akenda, Emmanuel Lokilo-Lofiko, Elisabeth Pukuta-Simbu, Adrienne Amuri-Aziza, Eddy Kinganda-Lusamaki, Prince Akil-Bandali, Ahidjo Ayouba, Martine Peeters, Eric Delaporte, Jean-Jacques Muyembe-Tamfum, Placide Mbala-Kingebeni, Antoine Nkuba-Ndaye, Véronique Kakiesse-Musumba and Steve Ahuka-Mundeke Show full author list Hide full author list

Viruses 2025, 17(10), 1327; https://doi.org/10.3390/v17101327 - 30 Sep 2025

Abstract

The ongoing mpox clade Ib outbreak was first detected in the eastern Democratic Republic of Congo (DRC) and was associated with sexual transmission. It emerged in Kamituga, a mining city and spread rapidly in surrounding health zones and reached cities like Bukavu and [...] Read more.

The ongoing mpox clade Ib outbreak was first detected in the eastern Democratic Republic of Congo (DRC) and was associated with sexual transmission. It emerged in Kamituga, a mining city and spread rapidly in surrounding health zones and reached cities like Bukavu and Goma. Here, we describe the clinical, epidemiological, and virological characteristics of the first case of clade Ib in Kinshasa, the capital city in the western DRC. The case involved a young adult woman from Kinshasa who reported unprotected sexual contact with an occasional partner, a former friend, and subsequently developed genital lesions, including vesicles and pustules. These lesions evolved and spread to the entire body, including the limbs, eyes, and soles. The diagnosis was confirmed by PCR and sequencing allowed us to assign clade Ib. We show that infection with mpox clade Ib through sexual transmission can lead to limbal nodular keratoconjunctivitis and focal conjunctivitis as complications. Importantly, these results suggest that clade Ib may have been circulating silently in Kinshasa prior to the official declaration by the Ministry of Health. This also raises concerns about the potential risk of global spread, as is currently being observed. Further studies are needed to investigate whether subsequent outbreaks of clade Ib in Kinshasa may have emerged independently of introductions from Kivu, pointing to a more complex pattern of co-circulation that could define the mpox epidemic in the capital. Full article

(This article belongs to the Special Issue Mpox (Monkeypox): From Neglected Tropical Disease to Emerging Global Pathogen)

► Show Figures

Figure 1

15 pages, 5275 KB

Open AccessArticle

Porcine Deltacoronavirus-Related Viruses in House Sparrows

by Daoqun Li, Jiayu Xu, Elizabeth M. Ames, Mingde Liu, Bikash Aryal, Maria Chellis, Ramon Zegpi Lagos, Christopher M. Tonra and Qiuhong Wang

Viruses 2025, 17(10), 1326; https://doi.org/10.3390/v17101326 - 30 Sep 2025

Abstract

Porcine deltacoronavirus (PDCoV) is an emerging enteric pathogen in pigs and a newly recognized zoonotic coronavirus in humans. Genetic analyses suggest that PDCoV originated from avian deltacoronaviruses, with sparrow deltacoronaviruses (SpDCoVs) being the most closely related. House sparrows (Passer domesticus) frequently [...] Read more.

Porcine deltacoronavirus (PDCoV) is an emerging enteric pathogen in pigs and a newly recognized zoonotic coronavirus in humans. Genetic analyses suggest that PDCoV originated from avian deltacoronaviruses, with sparrow deltacoronaviruses (SpDCoVs) being the most closely related. House sparrows (Passer domesticus) frequently visit farms and interact directly with pigs in barns, raising the possibility of interspecies transmission. We hypothesized that PDCoV can be transmitted between pigs and house sparrows. To investigate this, 200 house sparrows near Ohio swine farms were sampled and screened for gammacoronaviruses and deltacoronaviruses using RT-PCR targeting the conserved RNA polymerase region. Deltacoronaviruses and gammacoronaviruses were detected in 18.0% (36/200) and 5.5% (11/200) of fecal samples, respectively. Genomic sequence analysis of representative samples revealed that SpDCoVs are closely related to, but not direct ancestors of, PDCoVs. These SpDCoVs appear to be widespread in the U.S. Midwest and may contribute to PDCoV evolution. Attempts to isolate SpDCoV from these samples in embryonated chicken eggs and four cell lines were unsuccessful. Because coronaviruses frequently cross species barriers to cause epidemics and/or pandemics in humans and livestock, these findings underscore the need for ongoing surveillance of deltacoronaviruses in diverse wild animals, livestock, and humans to safeguard public health. Full article

(This article belongs to the Special Issue Emerging Microbes, Infections and Spillovers, 2nd Edition)

► Show Figures

Figure 1

14 pages, 858 KB

Open AccessArticle

In Vivo Characterization and Tissue Tropism of a Wild-Type Yellow Fever Virus Isolate from the 2017–2018 Brazilian Outbreak in C57BL/6 IFNAR1^−/− Mice

by Ana Luiza Campos Cruz, Natália Lima Pessoa, Ester Maria Paiva Silva, Sabrynna Brito Oliveira, Jéssica Pauline Coelho Souza, Samantha Stephany Fiuza Meneses Viegas, Anna Catarina Dias Soares Guimarães, Pedro Augusto Alves, Cintia Lopes de Brito Magalhães, Thomas P. Monath, Olindo Assis Martins-Filho, Andréa Teixeira-Carvalho, A. Desiree LaBeaud, Nidia Esther Colquehuanca Arias and Betânia Paiva Drumond

Viruses 2025, 17(10), 1325; https://doi.org/10.3390/v17101325 - 29 Sep 2025

Abstract

Yellow fever remains a significant public health concern in endemic regions of South America and Africa, where periodic outbreaks continue to challenge surveillance and control efforts. Despite the widespread use of vaccines and historical YFV strains in experimental settings, there is limited information [...] Read more.

Yellow fever remains a significant public health concern in endemic regions of South America and Africa, where periodic outbreaks continue to challenge surveillance and control efforts. Despite the widespread use of vaccines and historical YFV strains in experimental settings, there is limited information on the pathogenic behavior of contemporary wild-type isolates in animal models. To address this gap, this study aimed to develop and characterize a murine model infected with a wild-type YFV strain isolated in 2018, from Brazil’s largest sylvatic outbreak in decades. In this study, four-week-old male and female C57BL/6 IFNAR1^−/− mice were subcutaneously infected with WT YFV. Mice exhibited a nearly 50% survival rate and developed several clinical signs. Viral loads were assessed in serum and some tissues, collected either upon euthanasia of moribund animals or at the end point. YFV RNA was detected in all sampled tissues and serum. Infectious viral particles were identified in the brains of both sexes and in the testis. No statistically significant differences were observed between males and females in survival, clinical signs, or viral loads. Altogether, this study provides a robust and reproducible murine model for wild-type YFV infection, offering a valuable platform for investigating viral pathogenesis, host responses, and potential therapeutic interventions. Full article

(This article belongs to the Special Issue Advances in Alphavirus and Flavivirus Research, 3rd Edition)

► Show Figures

Figure 1

14 pages, 1118 KB

Open AccessReview

Congenital Human Cytomegalovirus and the Complement System

by Andrea Canto Garon, Yujun Liu and Fenyong Liu

Viruses 2025, 17(10), 1324; https://doi.org/10.3390/v17101324 - 29 Sep 2025

Abstract

Congenital human cytomegalovirus (HCMV) infection is the most common vertically transmitted viral infection, and it affects 1 in 200 live births worldwide. While neonates are often asymptomatic at birth, congenital HCMV infection can result in long-term complications, including microcephaly, sensorineural hearing loss, and [...] Read more.

Congenital human cytomegalovirus (HCMV) infection is the most common vertically transmitted viral infection, and it affects 1 in 200 live births worldwide. While neonates are often asymptomatic at birth, congenital HCMV infection can result in long-term complications, including microcephaly, sensorineural hearing loss, and neurodevelopmental abnormalities. Developing antiviral strategies for the treatment and prevention of congenital HCMV infections is a global public health priority. However, licensed anti-HCMV vaccines are not yet available, and therapeutic options for use during pregnancy remain limited. The complement system is a crucial component of the innate immune system that plays essential roles in both fetal development and maternal defense against infectious pathogens. In cases of congenital HCMV infection, complement may contribute to the successful containment of the virus, but dysregulation and overactivation could concurrently drive tissue-damaging inflammation. This review discusses the known roles of the complement system in fetal development and in HCMV pathogenesis and synthesizes existing research to develop the hypothesis that a dysregulated complement system is a key mechanism in the development of congenital HCMV-related pathogenesis and neurodevelopmental sequelae. We explore how HCMV may perturb the complement system during pregnancy and use one inhibitor example to illustrate the broader potential of targeting complement in limiting disease. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

► Show Figures

Figure 1

11 pages, 557 KB

Open AccessArticle

Genotype-Specific Vector Competence of Aedes albopictus for Japanese Encephalitis Virus Genotypes I, III, and V

by Bo-Ram Yun, Ji-Young Kwon, Dongmi Kwak and Hee Il Lee

Viruses 2025, 17(10), 1323; https://doi.org/10.3390/v17101323 - 29 Sep 2025

Abstract

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, poses a significant public health threat in Asia. Although Culex species are primary vectors, the role of Aedes albopictus in JEV transmission has gained attention under changing ecological conditions. This study evaluated the vector competence of [...] Read more.

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, poses a significant public health threat in Asia. Although Culex species are primary vectors, the role of Aedes albopictus in JEV transmission has gained attention under changing ecological conditions. This study evaluated the vector competence of Ae. albopictus for three JEV genotypes: I (GI), III (GIII), and V (GV). Laboratory-reared Ae. albopictus were orally challenged with each genotype, and infection rate (IR), dissemination rate (DR), head–thorax positivity rate (HTR, proxy for potential transmission), and transmission rate (defined as saliva positivity) were assessed at 7 and 14 days post-infection (dpi). Ae. albopictus showed marked genotype-specific differences. By 14 dpi, GV had the highest DR (100.0%) and HTR (71.7%), with viral RNA detected in 36.7% of TR. GIII showed moderate competence (76.9% DR, 39.3% HTR), but low TR (6.6%). In contrast, GI-infected mosquitoes exhibited minimal infection and negligible transmission, with viral RNA rarely detected beyond the midgut. These findings indicate that Ae. albopictus is highly competent for transmitting JEV genotype V and moderately for genotype III, but not genotype I, under laboratory conditions. This highlights its potential role in the transmission dynamics of emerging JEV genotypes and underscores the need for continued surveillance. Full article

(This article belongs to the Special Issue Mosquito-Borne Encephalitis Viruses)

► Show Figures

Figure 1

14 pages, 1194 KB

Open AccessReview

BCG Immunotherapy in Equine Sarcoid Treatment: Mechanisms, Clinical Efficacy, and Challenges in Veterinary Oncology

by Mariana Martins Monteiro, Elcidimar Lucas Aleixo de Castro, Ana Júlia Moaraes Pereira, Roberto Thiesen, Roberta Martins Crivelaro Thiesen and Felipe Masiero Salvarani

Viruses 2025, 17(10), 1322; https://doi.org/10.3390/v17101322 - 29 Sep 2025

Abstract

Equine sarcoids are the most common dermatological neoplasm in horses worldwide, associated with bovine papillomavirus (BPV) infection and characterized by high recurrence rates after conventional therapies. Bacillus Calmette–Guérin (BCG) immunotherapy has historically been used for sarcoid treatment, yet its role in contemporary veterinary [...] Read more.

Equine sarcoids are the most common dermatological neoplasm in horses worldwide, associated with bovine papillomavirus (BPV) infection and characterized by high recurrence rates after conventional therapies. Bacillus Calmette–Guérin (BCG) immunotherapy has historically been used for sarcoid treatment, yet its role in contemporary veterinary oncology remains debated. This narrative review critically examines the immunological mechanisms, clinical efficacy, and limitations of BCG in equine sarcoid therapy, while integrating insights from comparative oncology and One Health perspectives. A systematic search following PRISMA-based criteria identified 55 relevant studies published over the past four decades. Evidence indicates that BCG activates innate and adaptive immunity through TLR2/4 signaling, macrophage polarization, and enhanced CD8+ T-cell responses, leading to partial or complete sarcoid regression in select cases. However, therapeutic outcomes are highly variable due to heterogeneity in protocols (dose, strain, adjuvant use) and frequent adverse inflammatory reactions. Comparative analyses highlight that modern alternatives—such as cryotherapy, cisplatin-based protocols, and topical imiquimod—achieve higher efficacy and lower recurrence rates in many clinical settings. Although BCG is now rarely considered a first-line therapy, it remains relevant in resource-limited regions, such as the Amazon Biome, where cost-effectiveness and accessibility are critical. Future directions include randomized controlled trials, standardized protocols, and innovative approaches such as checkpoint inhibition, CRISPR-Cas9 targeting of viral oncogenes, and nanoparticle delivery systems. This review provides a balanced and data-driven synthesis of BCG immunotherapy, clarifying its historical contributions, current limitations, and translational opportunities for advancing equine and comparative oncology. Full article

(This article belongs to the Special Issue Viral Diseases of Domestic Animals)

21 pages, 1963 KB

Open AccessReview

Lipids, Tetraspanins, and Exosomes: Cell Factors in Orthoflavivirus Replication and Propagation

by Magda L. Benitez-Vega, Carlos D. Cordero-Rivera, Jose De Jesus Bravo-Silva, Ricardo Jimenez-Camacho, Carlos Noe Farfan-Morales, Jonathan Hernández-Castillo, Marcos Pérez-García and Rosa M. del Ángel

Viruses 2025, 17(10), 1321; https://doi.org/10.3390/v17101321 - 29 Sep 2025

Abstract

The cellular membrane is a dynamic structure composed of lipids and proteins organized into specialized domains that facilitate interactions between extracellular molecules and the intracellular environment. Tetraspanins are a family of transmembrane proteins involved in diverse cellular processes, including membrane stabilization and fusion, [...] Read more.

The cellular membrane is a dynamic structure composed of lipids and proteins organized into specialized domains that facilitate interactions between extracellular molecules and the intracellular environment. Tetraspanins are a family of transmembrane proteins involved in diverse cellular processes, including membrane stabilization and fusion, endocytosis, extracellular vesicle formation, and the organization of proteins and lipids at specific membrane sites known as Tetraspanin-Enriched Microdomains (TEMs). These lipid–protein interactions play a critical role in the replicative cycle of Orthoflavivirus, including dengue, Zika, and West Nile, by facilitating viral entry, replication, assembly, and egress. In addition, tetraspanins also regulate the biogenesis and function of extracellular vesicles, contributing to viral dissemination, persistent infection, and immune evasion. This review summarizes the current knowledge on the structural and functional aspects of tetraspanins, their interplay with lipids, and their emerging roles in the Orthoflavivirus replicative cycle. We also discuss how these insights may inform the development of antiviral strategies targeting membrane organization and virus–host interactions. Full article

(This article belongs to the Special Issue Dengue, Zika and Yellow Fever Virus Replication)

► Show Figures

Figure 1

14 pages, 3269 KB

Open AccessArticle

New Coronavirus in Colombian Caribbean Bats: In Silico Analysis Reveals Possible Risk of Interspecific Jumping

by Caty Martínez, Daniel Echeverri-De la Hoz, Alfonso Calderón, Yésica López, Camilo Guzmán, Ketty Galeano, Valeria Bertel, Bertha Gastelbondo-Pastrana and Salim Mattar

Viruses 2025, 17(10), 1320; https://doi.org/10.3390/v17101320 - 29 Sep 2025

Abstract

Since the appearance of the Severe Acute Respiratory Syndrome (SARS) virus, there has been increased interest in understanding the role of bats in the maintenance and circulation of coronaviruses. This study aimed to describe the phylogenetic and evolutionary relationships and antigenic architecture of [...] Read more.

Since the appearance of the Severe Acute Respiratory Syndrome (SARS) virus, there has been increased interest in understanding the role of bats in the maintenance and circulation of coronaviruses. This study aimed to describe the phylogenetic and evolutionary relationships and antigenic architecture of a new coronavirus detected in bats in the Department of Córdoba. In a surveillance study of pathogens of interest to public health, a bat Phyllostomus hastatus was captured. Rectal swabs samples were collected from the bats, and RNA was extracted and sequenced using NGS with MGI-G50 equipment. The results were analyzed using bioinformatics software. A contig of 28,619 nucleotides associated with the Coronaviridae family was obtained. Phylogenetic and molecular clock analyses of the ORF1ab gene revealed a novel divergent Alphacoronavirus that originated directly from an ancestral node. The analysis of the spike (S) protein and receptor-binding domain (RBD) is similar to that of humans (HCoV-229E) and porcine coronaviruses. In silico analysis suggests potential RBD interaction sites with human and pig cellular receptor aminopeptidase N. There is a possible risk of interspecies jumping of the new AlphaCoV/P. hastatus in humans and pigs. This is the first study to perform phylogenetic, evolutionary, and antigenic characterization of bat coronaviruses in Colombia. Full article

(This article belongs to the Special Issue Zoonotic and Vector-Borne Viral Diseases)

► Show Figures

Graphical abstract

15 pages, 6148 KB

Open AccessArticle

Subgenotype VII.1.1 Newcastle Disease Virus Evolution and Spread in the Russian Federation in 2019–2023

by Nelly A. Guseva, Sergey N. Kolosov, Nikolay G. Zinyakov, Anton A. Kozlov, Lydia O. Shcherbakova, Irina A. Chvala, Artem V. Andriyasov, Renfu Yin, Dmitry B. Andreychuk and Ilya A. Chvala

Viruses 2025, 17(10), 1319; https://doi.org/10.3390/v17101319 - 29 Sep 2025

Abstract

Between 2019 and 2023, 163 cases of subgenotype VII.1.1 Newcastle disease virus infection were registered in backyard poultry in the Russian Federation within the framework of epizootiological monitoring. Subgenotype VII.1.1 Newcastle disease virus was reported in a total of 18 different subjects of [...] Read more.

Between 2019 and 2023, 163 cases of subgenotype VII.1.1 Newcastle disease virus infection were registered in backyard poultry in the Russian Federation within the framework of epizootiological monitoring. Subgenotype VII.1.1 Newcastle disease virus was reported in a total of 18 different subjects of the Russian Federation. Most of the Newcastle disease outbreaks caused by the viruses of this subgenotype occurred in the autumn and winter period (60%). Further tests allowed for the determination of complete F and HN gene nucleotide sequences for 40 isolates. The results were used to perform the Bayesian analysis of F gene sequences with BEAST v.1.10.4 software. The obtained nucleotide substitution accumulation rates were practically non-dependent on the selected nucleotide substitution model and varied appreciably depending on the applied molecular clock model (0.0018 and 0.002 site-1year-1). The conducted study established that the formation of the ‘Russian’ NDV isolates of subgenotype VII.1.1 followed several stages. In the early 2000s, ancestral viruses belonging to subgenotype VII-d were detected in the Middle East and Eastern Europe. From these, through intermediate forms identified in Iraq around 2007–2008, a group designated as subgenotype VII-L emerged. This group gave rise to two sister clades: the Iranian subgenotype VII-L and the cluster of isolates from Russia and Poland, whose immediate common ancestor likely existed around 2015–2016, probably in Asia. Full article

(This article belongs to the Special Issue Evolution and Adaptation of Avian Viruses)

► Show Figures

Figure 1

15 pages, 1065 KB

Open AccessArticle

Pasteurized Milk Serves as a Passive Surveillance Tool for Highly Pathogenic Avian Influenza Virus in Dairy Cattle

by Abhinay Gontu, Manoj K. Sekhwal, Anastacia Diaz Huemme, Lingling Li, Sophia Kutsaya, Michael Ling, Nidhi Kajal Doshi, Maurice Byukusenge and Ruth H. Nissly

Viruses 2025, 17(10), 1318; https://doi.org/10.3390/v17101318 - 28 Sep 2025

Abstract

The emergence of H5N1 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b in dairy cattle across multiple U.S. states in early 2024 marks a major shift in the virus’s host range and epidemiological profile. Traditionally limited to bird species, the ongoing detection of [...] Read more.

The emergence of H5N1 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b in dairy cattle across multiple U.S. states in early 2024 marks a major shift in the virus’s host range and epidemiological profile. Traditionally limited to bird species, the ongoing detection of H5N1 in cattle, a mammalian host not previously considered vulnerable, raises urgent animal and human health concerns about zoonoses and mammalian adaptation. We assessed the feasibility of using commercially available pasteurized milk as a sentinel matrix for the molecular detection and genetic characterization of H5N1 HPAIV. Our aim was to determine whether retail milk could serve as a practical tool for virological monitoring and to evaluate the use of full-length genome segment amplification for extracting genomic sequence information from this highly processed matrix. Our results link HPAIV sequences in store-bought milk to the cattle outbreak and highlight both the potential and the limitations of retail milk as a surveillance window. Together, these findings provide evidence that influenza A virus RNA can be repeatedly detected in retail milk in patterns linked to specific supply chains, with genomic data confirming close relationships with the viruses circulating in cattle. Full article

(This article belongs to the Special Issue Bovine Influenza)

► Show Figures

Graphical abstract

Journal Description

Viruses

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI