Development of an S protein-based indirect ELISA for detecting IgA antibodies against porcine deltacoronavirus.

This paper examines the research output and impact of Veterinary Research Institutes (VRIs) of the Chinese Academy of Agricultural Sciences (CAAS), namely Shanghai Veterinary Research Institute (SHVRI), Harbin Veterinary Research Institute (HVRI), and Lanzhou Veterinary Research Institute (LVRI), to answer research questions. The study explores publication count, citation structure, h-index, most-cited articles, keyword trends, trend topics, co-authorship, thematic maps, and bibliographic coupling. The data is extracted from Scopus, covering publications from 2009 to 2023. Utilizing Excel, R (Biblioshiny), and VOSviewer (version 1.6.20, Leiden University, Netherlands), we found that VRIs of the CAAS demonstrated a steady upward trend in their research output, with SHVRI leading in top-cited articles, HVRI in citations and h-index, and LVRI in publications. Key journals include Veterinary Microbiology and Parasites and Vectors. Leading authors are Chan Ding (SHVRI), Xiaomei Wang (HVRI), and Xing-Quan Zhu (LVRI). Key research focus is on parasitology, virology, immunology, and molecular biology. SHVRI and HVRI's demonstrated focus is on virology, while LVRI's interest is in genetic analyses of the pathogens. Bibliographic coupling highlights core themes: SHVRI on Newcastle disease, Schistosoma japonicum, Toxoplasma gondii, and Porcine reproductive and respiratory syndrome virus; HVRI on African swine fever virus, Influenza viruses, and Porcine epidemic diarrhea virus; and LVRI on Toxoplasma gondii, the parasitic mitochondrial genome, and Foot and Mouth disease virus. Findings reflect CAAS's commitment to addressing critical animal diseases for China's development and food security.

Foot and mouth disease (FMD) is a highly contagious transboundary viral disease affecting livestock, causing significant economic losses. This sero-epidemiological study investigated FMD distribution and associated risk factors in cattle and buffaloes along the Pakistan-Afghanistan border. A total of 800 serum samples were collected from cattle (n = 610) and buffaloes (n = 190) and tested for antibodies against FMD viral structural proteins (SP) and non-structural proteins (NSP) using ELISA. Overall, 35.25% (282/800) of samples were NSP-positive, indicating natural infection. Serotype-specific analysis showed serotype O as the most prevalent (66.1%), followed by serotype A (50%) and Asia-1 (32%). Cattle exhibited higher FMD prevalence (37%; 95% CI: 33-40) than buffaloes (30%; 95% CI: 23-37). Significant spatial variations in SP and NSP Seroprevalence were observed across different areas. Risk factor analysis identified male sex, young age (1-2 years), crossbred and exotic breeds, summer season, large herd size, smallholders subsistence production systems, poor body condition, and animal movement as factors associated with significantly higher (p < 0.05) FMD circulation. These findings indicate that FMD is highly endemic in the border region and highlight the critical need for government-led mass vaccination campaigns, targeted risk-based surveillance, and stringent movement control to mitigate disease spread. Implementation of such control strategies is essential to safeguard livestock health and protect the regional economy from substantial losses.

Serodiagnosis of antibodies against the foot-and-mouth disease virus (FMDV) nonstructural protein 3ABC is essential for surveillance of infection and vaccination status. Here, we report a single-probe dual-readout peptide-based biosensor that combines electrochemical and fluorescence readouts for rapid and selective detection of anti-3ABC antibodies directly from serum. FMDV-inspired peptides, site-specifically labeled with 5(6)-carboxyfluorescein (FAM) or 7-methoxycoumarin-4-acetic acid, were immobilized on indium tin oxide electrodes via click chemistry. Antibody binding to the peptides produced a signal-off response in both modalities. FAM-probe electrodes exhibited superior performance, achieving detection limits of 0.38-1.14 (electrochemical) and 0.49-1.49 ng mL-1 (fluorescence) with <3% interference from nontarget antibodies. In validation with 36 bovine, ovine, and caprine sera, the platform distinguished infected from vaccinated animals with 93 ± 2% accuracy (electrochemical) in only 30 min. This low-cost dual-readout sensor demonstrates a broadly adaptable strategy for high-accuracy serodiagnostics, provided that suitable redox-active fluorophores and antibody-recognizable peptide epitopes are employed, with potential for portable bioanalytical devices.

Foot and Mouth Disease (FMD) is one of the most devastating animal diseases. Infected animals, such as swine, develop vesicles, often leading to morbidity or depopulation of exposed herds. Current FMD diagnosis relies on serologic and immuno-based methods, which commonly encounter cross-reactivity and cost issues. Therefore, a simple and portable diagnostic tool would greatly aid its detection efforts. This study generated a novel aptamer sequence targeting viral protein 1 (VP1) of serotype O FMD virus (FMDV) by Systematic Evolution of Ligands by Exponential Enrichment (SELEX). The generated FMDV VP1-specific aptamer sequence was characterized and incorporated into an Aptamer-linked Immobilized Sorbent Assay (ALISA)-based microplate platform to detect FMDV VP1. Results showed that the aptamer, FMDV Apt, had an estimated dissociation constant (Kd) of 14 ± 8.6 nM, showing strong affinity for VP1 of FMDV. A concentration-dependent linear relationship (R2 = 0.9354) within a concentration range of 0.50 ng/mL – 5.0 ng/mL of FMDV VP1 protein was observed. The limit of detection (LOD) was determined to be 1.3 ng/mL, and the limit of quantification (LOQ) was approximately 4 ng/mL. Moreover, the FMD ALISA did not exhibit cross-reactivity when tested with high concentrations (500 ng/mL – 2,000 ng/mL) of non-targets, indicating its robustness and potential application in other detection platforms. The newly developed screening tool would facilitate efficient and inexpensive monitoring of potential biohazard risks posed by FMDV.

Despite mounting evidence that small ruminants have a role in disease transmission, the epidemiological status for foot-and-mouth disease (FMD) in Nigeria is inadequate and under-reported. In this study, we looked at the seroprevalence of foot and mouth disease virus in goat species in Port Harcourt, River State. A total of 356 blood samples from goats were obtained during slaughter at seven different abattoirs in Port Harcourt, Rivers State. Samples were processed and analysed for FMD using an in-house 3ABC competitive Enzyme-Linked Immunosorbent Assay (ELISA), as well as serotypes A, O, SAT 1, and SAT 2 specific ELISA. An overall seroprevalence of 37.1% (32.21 - 42.1) for FMD was recorded. The seroprevalence based on location revealed a higher prevalence in Emenike 85.2% (Cl: 73.8 - 92.9), followed by Ruememe 60% (CI: 46.4 - 73.6), Mile3 54.0% (Cl: 41.6 - 66.0), Aluu 42% (Cl: 28.2 - 56.0), Rumokoro 38.7% (Cl: 26.0 - 52.9), Choba 29.3% (Cl: 16.9 - 44.5) respectively while, Rumosi had the least seroprevalence of 8.2% (Cl: 2.6-18.5). This study also detected the circulation of FMD virus serotype O. The study demonstrates high seroprevalence of FMD in goats. Thus, a comprehensive surveillance and vaccination campaign is required to check the silent amplification and transmission of the virus to other animals

Young children are susceptible to infectious diseases due to their developing immune systems and close contact in group care settings. During the coronavirus disease 2019 (COVID-19) pandemic, infection prevention measures may have altered the epidemiology of common childhood infections, yet evidence on variations by facility type and region remains limited. In this study, the occurrence of COVID-19 and child-specific infectious diseases in childcare and early childhood education facilities in Japan was examined with particular focus on facility type and regional population density. A nationwide mail survey was conducted between January and April 2023 among 5,000 facility managers, and 710 valid responses were analysed. Over 90% of facilities reported at least one COVID-19 case within the previous year. The occurrence of child-specific infectious diseases, including adenovirus infection, hand, foot, and mouth disease, herpangina, streptococcal infection, norovirus infection, and respiratory syncytial virus infection, was lower in kindergartens serving children aged ≥ 3 years than in children in daycare centres or certified childcare centres (p < 0.05). Hand, foot, and mouth disease and influenza virus infection showed significant linear associations with population density, with lower reporting rates in less densely populated regions (p < 0.05). Conversely, rotavirus infection was more frequently reported in low-density regions (p < 0.05), whereas other child-specific infectious diseases exhibited heterogeneous and non-linear regional patterns, indicating that population density alone does not explain regional variation. These results highlight the importance of facility-, age-, and region-specific approaches to infection prevention in childcare settings beyond the COVID-19 pandemic.

Aphthovirus is responsible for foot-and-mouth disease (FMD) in cloven-hoofed animals, a highly infectious disease that has significant economic repercussions in various countries, including Indonesia. The present study aimed to use reverse transcription polymerase chain reaction (RT-PCR) to detect FMD in suspected Bali cattle in West Lombok, Indonesia. The current study was an observational, descriptive investigation conducted from July to August 2025, collecting 15 swab samples from male Bali cattle with an average weight of 210 kilograms and an average age of 2 years old. The samples were collected via purposive sampling from cattle demonstrating clinical signs of FMD, specifically from oral vesicular fluid. The samples were sourced from two smallholder farms in West Lombok; farm one, with 12 samples, and farm two, with three samples. The FMD was identified with a prevalence rate of 20% (3 out of 15), and a 328 bp DNA fragment was detected during gel electrophoresis. The current result indicated that the virus pathogen was detected in 20% of samples, and RT-PCR can be used as a high-sensitivity diagnostic method for this disease. Keywords: Bali cattle, Foot-and-Mouth disease, PCR, Reverse transcription

Foot and mouth disease is a contagious viral disease infecting ungulates, with great economic impact on farmers' income; it is primarily controlled using inactivated vaccines, which have certain limitations, such as short-lived immunity and a lack of mucosal immunity at the portals of virus entry. The present approach aims to exploit the efficiency of chitosan nanoparticle-encapsulated inactivated type 'O' FMDV antigen (FMDV-CS-NPs) to induce mucosal and systemic immune responses in a guinea pig animal model through intranasal and intramuscular administration in comparison with the conventional inactivated, mineral oil-adjuvanted vaccine that is administered systemically. In this study, the FMDV-CS-NPs were prepared by ionotropic gelation, followed by incubation; were characterized for their physical properties and in vitro antigen release; and were found to encapsulate a good amount of antigen. The prepared nanoparticles were assessed for their ability to induce humoral and cell-mediated immune responses by SNTs; indirect ELISAs for serum IgG, IgG1, and IgG2; and nasal washing sIgA and lymphocyte proliferation assays. The preparation induced comparatively more measurable sIgA and systemic immune responses with the intranasal and intramuscular routes of administration, respectively, which are attributable to a specific interaction between the positively charged chitosan and the negatively charged mucosal surface and cell membrane. The challenge infection protected 87.5% of the animals in the FMDV-CS-NP I/M group, followed by 77.7% in the FMDV-CS-NP I/N and inactivated vaccine groups. The outcomes of this study in guinea pigs highlight that chitosan nanoparticle-based vaccine formulations could be employed as a promising antigen delivery system for targeted delivery, devoid of any adverse effect, to induce protective immune responses.

The foot and mouth disease virus (FMDV) poses a heavy burden on the global swine industry, underscoring the urgent need for long-term protective vaccines to control FMDV infection. Dendritic cells (DCs) are critical in activating innate immune cells and initiating adaptive immune responses. However, the role of DCs in FMDV infection remains poorly understood. In this study, we developed a mouse model lacking the type I interferon receptor for infection, followed by single-cell RNA sequencing to generate a high-resolution map of DCs in the spleens of FMDV-infected mice. Next, we established an evaluation system to investigate the antigen-presenting capacities of gene-edited DCs and mice. The results reveal that FMDV infection alters the proportions of DC subsets and significantly suppresses antigen processing and presentation. Additionally, we identified Cmss1 as a novel host factor that antagonizes the inhibition of the antigen-presenting process caused by FMDV infection, thereby limiting FMDV pathogenicity in mice. These findings provide valuable insights into potential antiviral strategies against FMDV infection.IMPORTANCEIn this study, we first developed C57BL/6 mice lacking the type I interferon receptor as an infectious model, which was subjected to single-cell RNA sequencing analysis of DC features in response to FMDV infection. We identified VP419-30 as an immunodominant CD8+ T cell epitope of FMDV and established an in vitro system to evaluate the antigen-presenting capacities. Based on these findings, we validate Cmss1 as a novel host factor in antigen processing and presentation during FMDV infection. Since DCs play critical roles in mediating immune responses, our findings comprehensively characterize the immune features of dendritic cells for the first time and present a new mechanism through which the host defends against FMDV infection, suggesting Cmss1 as a novel potential target for antiviral therapies.

Foot and Mouth Disease (FMD) is a transboundary viral disease caused by the Foot and Mouth Disease Virus (FMDV), which is classified into seven serotypes (A, O, C, Asia 1, SAT 1, SAT 2 and SAT 3) within the Picornaviridae family and Aphthovirus genus that affects both wild and domesticated cloven-hoofed animals, leading to high morbidity and substantial economic losses. In Bangladesh, three serotypes of FMDV: O, A, and Asia 1 predominantly affect cattle, remarkably more than one serotype in each year. Disease prevention relies on vaccination against the prevalent serotypes. However, despite extensive vaccination efforts, FMD outbreaks continue to occur due to high variability in FMDV, particularly of the VP1 gene, which gives rise to new variants and complicates control strategies. This review aims to Meta-analyze the epidemiological characteristics and functional divergence of prevalent FMDV serotypes in Bangladesh from 2010 to 2024 by examining their evolutionary history and dynamics based on partial VP1 gene sequences retrieved from NCBI GenBank database. It explores the FMDV serotypes, host, ecology, annual prevalence, sequence length, antigenic regions, evolutionary relationships, genotypes, and divergence, as well as amino acid variables in the BC loop, G-H loop and C-terminus region of the VP1 gene of prevalent FMDV serotypes. Additionally, the study addresses the similarity of currently used FMDV vaccine strains` VP1 amino acid sequences compare to VP1 amino acid sequence of prevalent FMDV serotypes, underscoring the need for updated vaccines that target circulating strains for effective disease control.

ABSTRACT T and B lymphocytes protect against the foot and mouth disease virus (FMDV). They are essential for long-term immunity and viral clearance, but their immunological features in FMDV infection remain unknown. Here, we performed single-cell RNA sequencing (scRNA-seq) and conducted integrative analyses to determine cell composition, gene expression, cell-cell communication state, and regulatory network of T and B cells in the spleen of FMDV- and mock-infected mice. Our results revealed variational compositions of immune cells on the subsets level. Additionally, we determined the reshaping of several essential pathways in T and B cells, such as the inhibition of antigen-presentation capacity. Finally, the virus-induced shaping of immune patterns, including cell-cell communication and regulatory networks, was also characterized during FMDV infection. Overall, our research provides valuable insights and resources for understanding the adaptive immune response in FMD.

Hand–foot–mouth disease (HFMD), primarily caused by human enteroviruses (EVs), poses a public health challenge, particularly among infants, due to a lack of effective therapies. Elucidating the molecular interplay between EVs and the host immune response is crucial for developing antiviral treatments. Recent studies have highlighted the significance of long non-coding RNAs (lncRNAs) in regulating host–pathogen interactions; however, the mechanisms of lncRNAs in EV infection remain poorly unexplored. Here, we identified a highly inducible nuclear lncRNA, LINC1467, that is upregulated in response to HFMD-related EV infection. Functional analyses revealed that LINC1467 suppresses viral replication. Mechanistically, LINC1467 interacts with nuclear import receptor Importin 8 (IPO8) to form the LINC1467/IPO8/p65 complex, facilitating the phosphorylation and nuclear translocation of p65, thus promoting the expression of pro-inflammatory cytokines and activating the NF-κB pathway. The antiviral function of LINC1467 was further validated in a mouse model of viral infection. These findings uncover a novel lncRNA-mediated regulatory mechanism in the innate immune response and highlight LINC1467 as a promising target for future antiviral strategies against HFMD-related EVs.

Positive-sense RNA virus infections induce vesicle formation within host cells to support RNA replication. By extracting and purifying foot-and-mouth disease virus (FMDV) replication complexes and comparing host cells and replication complexes through targeted lipidomics and proteomics analyses, we found that FMDV enriches host cell proteins and polyunsaturated fatty acids in viral replication complexes (VRCs) to facilitate their formation. On the basis of these findings, we propose a model in which VRCs progress from single-membrane vesicles to multi-membrane vesicles (MMVs) during FMDV replication, a process that requires coordinated contributions of host cell proteins and organelle membranes derived from multiple organelles. Our study showed that, as infection advances, FMDV converts single-membrane vesicles (SMVs) into MMVs, which aggregate to expand the surface area of the replication platform and enhance replication efficiency. These membrane structures function in FMDV replication; the endoplasmic reticulum undergoes curling and folding to support VRC assembly. Additionally, some VRCs possess outward-facing openings that permit material exchange. These findings reveal unexpected similarities between FMDV and distantly related positive-strand RNA viruses, suggesting that shared host cellular pathways are exploited to construct membrane-bound replication factories.

Hand, foot, and mouth disease (HFMD) can show severe clinical symptoms in children and infants, such as fever, mouth ulcers, and vesicular rashes on the palms and feet.Enterovirus 71 (EV71) is the leading cause of this disease.In this study, we investigated the antiviral effect of soluble scavenger receptor type B2 (SCAB2, CD36) to develop a new therapeutic approach for HFMD.Soluble SCAB2: Fc was generated by using the human IgG1 Fc region.The SCAB2 gene was cloned into the expression plasmid with human IgG1 Fc sequences (SCAB2:Fc/PCK).SCAB2:Fc/PCK plasmid was transfected into HEK293T cells for 72 hours.Then the cell protein was extracted, and the culture supernatant was collected.The supernatant SCAB2:Fc protein was concentrated, and its concentration was measured using a human IgG1 ELISA kit.SCAB2:Fc strongly blocked the EV71 target cell entry in a dose-dependent manner.The antiviral activity of SCAB2:Fc was observed by western blot analysis and reverse transcription PCR (RT-PCR).VP1 capsid protein and virus-positive-strand RNA were significantly decreased in 100 ng/ml of SCAB2:Fc treatment.Transcription factor, eIF4G1, and cleaved caspases3 levels were reduced considerably with SCAB2:Fc treatment.Moreover, inhibiting virus infection strongly suppressed virus replication and cell proliferation regulating MAPK signaling.The phosphorylation of p38 and ERK1/2 was significantly decreased by SCAB2:Fc treatment.These data suggested that SCAB2:Fc inhibited EV71 infection and virus replication-induced MAPK signaling activity.In this study, the antiviral effect of soluble SCAB2 was investigated to develop an EV71 treatment.Soluble SCAB2:Fc showed potent antiviral activity in vitro, and it could be a potential candidate material to use as a therapeutic drug for EV71induced HFMD.

Passive immunity against foot and mouth disease virus (FMDV) is important till the time of primary vaccination as it causes high mortality in the calf. Hence, it is necessary to determine the vaccination window of the dam during the pregnancy. Accordingly, serial sera were collected at monthly interval (0-5 months) from the calves (n = 15) whose dams were last vaccinated during 80-110 days of pregnancy with an oil-adjuvanted inactivated FMD vaccine covering serotypes O, A, and Asia1. First blood sample from the calf was collected 2-3 days post-birth while blood sample was collected from the dam 3-5 days before expected calving. Virus neutralization (VN) test was performed and the resulting neutralizing antibody titer was compared with the expected protective titer. One sample t test revealed that the calves had passive immunity at birth for all the three serotypes (P > 0.05). Mixed model ANOVA indicated that the VN titer declined significantly by 2 months for serotype O and by 3 months for other two serotypes (P < 0.05). Antibody response to serotype O was highly variable among the calves as evidenced by a random effect of 73%. Though a positive correlation was expected in the VN titer between the dam and calf, no such result was found for any of the three FMDV serotypes. It was concluded that the protective window of FMD vaccination of dam is beyond 110 days for all the three serotypes of FMDV to confer adequate passive immunity to the calf.

Brucellosis, a zoonotic infection caused by the intracellular pathogen Brucella, leads to chronic multi-organ damage. Currently, rapid, accurate, and sensitive diagnostic technologies are crucial for the prevention and control of brucellosis. This study describes the development of a chemiluminescent immunoassay (Bru-CLIA) for sheep and bovine brucellosis antibody detection, utilizing Brucella abortus strain A19 lipopolysaccharide-coated magnetic particles (LPS-MPs) as the serum antigen and acridinium ester-labeled recombinant streptococcal protein G (AE-SPG) for signal generation. After optimizing the assay’s parameters, the Bru-CLIA demonstrated a sensitivity of approximately 1 IU/mL and 2 IU/mL for detecting sheep and bovine brucellosis, respectively. No cross-reactivity was observed with sera from animals immunized with Escherichia coli O157:H7, Mycobacterium tuberculosis, Vibrio cholerae, Legionella, Salmonella, Foot and Mouth Disease virus types O and A, Bovine viral diarrhea virus, Sheep contagious pleuropneumonia, Goat pox virus, or Peste des Petits Ruminants virus, indicating strong specificity. The testing of 81 sheep serum samples and 96 bovine serum samples revealed that Bru-CLIA showed 87.65% and 93.75% concordance with the ID-VET commercial kits for sheep and bovine brucellosis detection, respectively. These results demonstrate that Bru-CLIA offers high specificity, sensitivity, repeatability, and reliability, making it a viable rapid diagnostic tool for the epidemiological surveillance of brucellosis.

Foot-and-mouth disease is an important transboundary animal disease with a significant economic impact. The high mutation rate of the foot-and-mouth disease virus leads to the emergence of new genotypes, which necessitate the detection, identification and surveillance of FMD. The current study was conducted to detect and characterize the circulating FMD viruses in Iran between November 2019 and September 2023, based on the VP1 sequence analysis. Three serotypes O, A and Asia 1 were detected. In this study, the first appearance of SA-2018 lineage in Iran was reported, along with the dominance of ANT-10 and PUN-16 sublineage of O/ME-SA/PanAsia-2 lineage. Meanwhile, the VP1 nucleotide sequences of serotype A viruses classified them to the A/ASIA/Iran-05/FAR-11; and sequences of Asia 1 viruses classified them to the Sindh-08 lineage. This study provided an update on the epidemiology of FMD virus in Iran and presented the emergence of the SA-lineage. Another finding was that even though the samples were taken from vaccinated animals, the positivity rate was high. Regarding the comparison results between field and vaccine nucleotide sequences, effective vaccination and the application of restrictions on the movement of animals are necessary.

Co-circulation of multiple serotypes of foot and mouth disease virus among susceptible multispecies animal population in India during 2021-2022.

Australia's large populations of feral and extensively farmed livestock pose challenges to implementing response plans in the event of an Emergency Animal Disease outbreak. This study aimed to determine if a “Destroy and Let Lie” approach to carcass disposal (leaving carcasses in situ to decompose naturally after field euthanasia) would reliably inactivate Foot and Mouth Disease virus (FMDV) and African Swine Fever virus (ASFV) under Australian conditions. Ninety‐five animals (24 each of cattle, sheep, goats and 23 pigs) were used across six trials, conducted in winter and summer, in three locations in Eastern Australia. After euthanasia, temperature and pH were measured at six internal anatomical sites hourly for 24 h, then less frequently for a further 24 h. Data were compared with published FMDV and ASFV inactivation thresholds to assess the likely effectiveness of field decomposition in reducing viral infectivity. Tissue pH levels generally declined for the first 6–12 h postmortem. Based on a pH threshold of <6, FMDV would be reliably inactivated in the thoracic and abdominal cavities and deep and superficial muscle sites. In contrast, no porcine tissues at any location in any season would provide inactivation of ASFV, based on a pH threshold of <3.9. “Destroy and Let Lie” appears to be a suitable approach to reduce risk of FMDV transmission from carcasses that cannot be disposed of using conventional means under Australian field conditions. This would not be the case for an ASF outbreak, where expected viral inactivation would be minimal.