Search Results (1,298)

African swine fever (ASF) is a viral disease of domestic and wild pigs that has re-emerged as a major transboundary disease. Modelling using mechanistic, statistical, and machine learning (ML) approaches plays a key role in understanding ASF transmission and informing disease control, but the literature remains fragmented. To synthesise global ASF modelling efforts, we systematically reviewed studies applying these three approaches. We examined temporal and geographic trends, modelling objectives, explanatory variables, and model evaluation practices. A total of 151 papers published through 2024 met the inclusion criteria. Mechanistic (54.3%) and statistical (40.4%) approaches predominated, whereas ML (9.3%) was increasingly applied in recent years. Mechanistic models were primarily used to assess control strategies (48.8%) and transmission drivers (41.5%), statistical models to identify risk factors (63.9%) and spatiotemporal spread (32.8%), and ML for environmental suitability modelling (64.3%). Most were published from 2011 (99.3%) and focused on Europe (43.0%) and Asia (26.5%). Model evaluation remained inconsistent, with mechanistic papers frequently lacking model output uncertainty quantification (47.0%) and statistical papers often omitting model adequacy assessment (49.2%) and assumption checking (50.8%). Overall, ASF modelling approaches have developed complementary methodological roles, while geographic underrepresentation, limited representation of some transmission pathways, and inconsistent model evaluation remain important gaps. Full article

Classical swine fever (CSF) is a highly contagious transboundary animal disease that causes major economic losses to the global swine industry and remains notifiable to the World Organisation for Animal Health (WOAH). Handling and transport of infectious classical swine fever virus (CSFV)-positive samples require biosafety level 3 (BSL-3) containment, limiting diagnostic capacity and interlaboratory exchange in many regions. In this study, we evaluated the efficacy of PrimeStore^® Molecular Transport Medium (PS-MTM) for eliminating detectable CSFV infectivity while preserving viral ribonucleic acid (RNA) detectability for downstream molecular detection. Validation assays were performed using the CSFV Alfort/187 reference strain and clinical samples collected from pigs experimentally infected with the Catalonia01 and Margarita CSFV strains. Residual infectivity was assessed by virus isolation, whereas viral RNA detection and stability were evaluated using the WOAH-recommended real-time reverse transcription quantitative polymerase chain reaction(RT-qPCR) assay. Following PS-MTM treatment, no residual infectivity was detected in either cell culture-derived virus stocks or clinical samples, including extensive replicate testing and three subsequent blind passages. RT-qPCR analyses confirmed preservation and stability of detectable CSFV RNA for at least 60 days under the storage conditions evaluated, including refrigerated storage and room temperature storage for Catalonia01-derived samples. Overall, these findings demonstrate that PS-MTM eliminates detectable CSFV infectivity while preserving viral RNA for molecular diagnosis. The implementation of PS-MTM may facilitate safer handling, transport, and interlaboratory exchange of CSFV-positive samples, contributing to improved biosafety, diagnostic harmonization, and global surveillance capacity for this transboundary animal disease. Full article

Oxidative stress is closely associated with mitochondrial dysfunction and contributes to the development of several human diseases. Among antioxidant compounds, ASC and NAC are widely used for their cytoprotective and redox-regulating properties; however, their direct effects on specific aspects of mitochondrial bioenergetics are only partially characterized. In the present study, we investigated the effects of ASC and NAC, individually and combined, on Mg²⁺-dependent F₁F_O-ATPase hydrolysis, mitochondrial free thiol content and respiration in isolated swine heart mitochondria. ASC significantly stimulated F₁F_O-ATPase activity in a concentration-dependent manner, whereas kinetic analysis indicated a mixed uncompetitive activation mechanism. In contrast, NAC alone did not significantly affect F₁F_O-ATPase activity but abolished the stimulatory effect of ASC when the two compounds were combined. Both ASC and NAC increased mitochondrial free thiol content, although no change was observed under combined treatment conditions. Mitochondrial oxygen consumption analysis revealed substrate-dependent effects of the two antioxidants on electron transport. Overall, ASC and NAC exerted distinct direct actions on isolated mitochondria, and their combination did not produce additive or synergistic effects. These findings provide new insights into the direct modulation of mitochondrial function by antioxidant compounds and may contribute to expanding understanding of their potential therapeutic and dietary supplement applications, particularly when combined. Full article

As a highly contagious infectious disease in the swine industry, porcine reproductive and respiratory syndrome (PRRS) can cause reproductive disorders in sows and respiratory diseases in piglets, resulting in sustained economic losses. Nonstructural protein 10 (NSP 10), as one of the core components of the replication and transcription complex of PRRS virus (PRRSV), has both helicase and adenosine triphosphatase activities, and has the potential as a diagnostic marker. In this study, NSP10 recombinant protein was used as coating antigen, and an indirect ELISA method for PRRSV NSP10 detection was established by square matrix titration. After optimizing the assay parameters, high specificity (no reactions with other pig viruses), high sensitivity (able to detect antibodies even when the positive blood sample was diluted 1280 times), and excellent reproducibility (less than 10% variation) were shown. Therefore, the NSP10 indirect enzyme-linked immunosorbent assay (ELISA) developed in this study provides an effective technical means for enhancing PRRSV surveillance in swine herds, thereby establishing a solid foundation for the clinical diagnosis and comprehensive prevention and control of PRRSV. Full article

Porcine epidemic diarrhea virus (PEDV) G2c variants have recently emerged, posing significant challenges to swine health management. As a major coronavirus affecting the swine industry, PEDV exhibits extensive genetic variability, which has greatly complicated disease control. Current vaccines provide suboptimal protection under field conditions. Therefore, the isolation of recently circulating strains and the establishment of a robust reverse genetics system are critical for advancing the study of emerging variants and facilitating rational vaccine development. In this study, a PEDV field strain designated PEDV-BJ-2023 was isolated from diarrheic piglets in Guizhou, China. Phylogenetic analysis based on the complete genome and spike gene classified PEDV-BJ-2023 within the emerging G2c lineage. To facilitate functional studies, a full-length infectious cDNA clone was constructed using transformation-associated recombination cloning in yeast. Furthermore, an enhanced green fluorescent protein reporter virus was generated via CRISPR/Cas9-assisted homologous recombination by inserting an EGFP-2A cassette upstream of the nucleocapsid gene. The recombinant viruses displayed virion morphology and plaque characteristics similar to those of the parental wild-type PEDV-BJ-2023 strain, although the parental virus exhibited faster replication during the early stage of infection in vitro. In 5-day-old piglets, all three viruses caused severe diarrhea, weight loss, and intestinal lesions; however, recombinant viruses exhibited slightly reduced viral shedding and pathogenicity, with rPEDV-EGFP being the most attenuated. Notably, rPEDV-EGFP maintained stable EGFP expression over eight serial passages. This study establishes a reverse genetics platform for an emerging G2c PEDV strain and provides a stable fluorescent reporter virus, offering valuable tools for visualizing viral infection and investigating virus–host interactions. Full article

Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), is a major infectious disease that poses a severe threat to the global swine industry. To investigate the role of miRNAs in the infection and susceptibility of PRRSV, four miRNA libraries were constructed and sequenced from PRRSV-infected and mock-infected of Tibetan pigs and Large White pigs at 7 days post-infection. A novel miRNA, miR-novel-80, was differentially expressed between PRRSV-infected and mock-infected porcine alveolar macrophages from 2 pig breeds. Importantly, the over-expression of miR-novel-80 inhibited the replication of a PRRSV-1 strain and multiple lineages (L1, L5, and L8) of PRRSV-2 strains in a dose-dependent manner. Bioinformatic predictions and experimental validation demonstrated that miR-novel-80 restricts viral replication through a dual antiviral mechanism. Directly, it targets the PRRSV nsp1-coding region within the ORF1a to suppress viral proliferation. Indirectly, miR-novel-80 specifically down-regulates the expression of host factor CXXC finger protein 4 (CXXC4). This reduction relieves the suppression of the Wnt/β-catenin signaling pathway, which in turn activates NF-κB-dependent innate immune responses to further inhibit PRRSV infection. Collectively, this study investigates the biological characteristics of miR-novel-80 and unveils its underlying molecular mechanisms in restricting PRRSV infection in vitro. However, its biological function and anti-PRRSV therapeutic effect in vivo need further investigation. Full article

Timely detection of specific antibodies against foot-and-mouth disease virus (FMDV) is critical to effective prevention and control of the disease. In this study, we developed a competitive chemiluminescent enzyme immunoassay (cCLEIA) based on recombinant FMDV VP2 protein (FMDV-VP2 cCLEIA) for simultaneous detection of antibodies against FMDV serotypes O and A in serum samples. Using a cut-off of 35% percentage inhibition (PI), the FMDV-VP2 cCLEIA achieved a relative sensitivity of 101.5% and a relative specificity of 102% compared with commercial FMDV serotypes O and A liquid-phase blocking ELISA (LPBE) kits. The assay showed high specificity for detection of antibodies against FMDV serotypes A and O, with no cross-reactivity observed against positive sera for classical swine fever virus, porcine reproductive and respiratory syndrome virus, and Senecavirus A. Both intra-batch and inter-batch coefficients of variation were below 15%, confirming excellent assay reproducibility. The testing of 40 field serum samples yielded a positive detection rate of 95% using the FMDV-VP2 cCLEIA, compared with 92.5% using the FMDV serotypes O and A LPBE kits. In conclusion, the FMDV-VP2 cCLEIA developed is a rapid, sensitive assay for simultaneous detection of antibodies against FMDV serotypes O and A, which may offer a valuable tool for foot-and-mouth disease (FMD) surveillance and control programs. Full article

African swine fever virus (ASFV) causes African swine fever (ASF), a highly lethal disease in pigs. Vietnam has approved two ASF live-attenuated vaccines (LAVs), but their efficacy and safety remain controversial, and no reliable, highly effective commercial ASF vaccine is available yet. Humoral immunity plays an important role in protection against ASFV infection. However, there is still controversy regarding whether ASFV infection can induce antibodies with neutralizing activity. Antibody-dependent cellular cytotoxicity (ADCC), as an antibody-mediated protective mechanism, offers a novel perspective for screening protective ASFV antigens. This study evaluated five structural proteins (pCP312R, pA104R, pA151R, p17, and pF317L) as subunit vaccine candidates based on their ability to induce antibodies that inhibit viral replication and mediate ADCC. The recombinant proteins were expressed in Escherichia coli, purified, and used to immunize pigs. Immune sera collected two weeks after the third immunization were tested for their ability to inhibit ASFV replication in porcine alveolar macrophages (PAMs) using rASFV-Gluc/EGFP. ADCC activity was assessed using a stable HEK293T-p17 cell line as target cells and porcine peripheral blood mononuclear cells (PBMCs) as effectors, with cytotoxicity measured by lactate dehydrogenase release. All five recombinant proteins were successfully expressed and purified. Immunization with pCP312R, pA104R, p17, and pF317L induced the production of specific antibodies in pigs, but only anti-p17 antibodies significantly inhibited ASFV replication in PAMs. The p17 is highly conserved across different ASFV genotypes and is predicted to contain a transmembrane domain. Anti-p17 antibodies effectively mediated PBMCs to specifically kill target cells, demonstrating significant ADCC activity. Moreover, the HEK293T-p17 cell line was specifically recognized by anti-ASFV sera. These findings indicate that p17 is a dual-functional antigen capable of eliciting antibodies that both inhibit viral replication and mediate ADCC in vitro. Furthermore, we have developed an in vitro platform for screening protective ASFV antibodies based on viral inhibition and ADCC, providing candidate targets for the development of next-generation ASF subunit vaccines. Full article

African swine fever (ASF), caused by African swine fever virus (ASFV), is a highly contagious disease that has brought severe economic losses to the global swine industry. ASFV dUTPase is a key enzyme modulating viral nucleotide metabolism and genome stability, serving as a specific structural target for anti-ASF lead discovery. Based on the crystal structure of ASFV dUTPase (Georgia 2008/1 strain), we established a molecular docking model to virtually screen a Traditional Chinese Medicine (TCM) compound library following ADME-based filtration. We further conducted 100 ns molecular dynamics (MD) simulations via GROMACS and calculated binding free energies using the MM/PBSA method, followed by in vitro enzymatic inhibition assays for verification. Four candidate compounds, namely Salvianolic acid B, Kukoamine B, Ligustroflavone and 9‴-Methyl salvianolic acid B, showed favorable structural accommodation and binding potential. In vitro tests indicated that Ligustroflavone and 9‴-Methyl salvianolic acid B exhibited preliminary inhibitory activity against ASFV dUTPase, with IC₅₀ values of 1.87 mM and 0.92 mM, respectively, while Kukoamine B showed no inhibitory effect. This study identified potential TCM-derived lead molecules targeting ASFV dUTPase, providing new references and candidate compounds for the development of anti-ASF therapeutics. Full article

Porcine reproductive and respiratory syndrome, a highly contagious disease, poses a severe threat to the global swine industry. Its causative agent, PRRSV, induces reproductive disorders (abortion, stillbirth) in pregnant sows and respiratory disease in piglets. The host immune system is disrupted by PRRSV, and no specific antiviral drugs are currently available. Thus, vaccination is regarded as the primary strategy for PRRS prevention and control. GP4, a key minor structural protein of PRRSV with an estimated molecular weight of 32 kDa, contains four conserved N-glycosylation sites at residues 37, 84, 120 and 130. Critical neutralizing epitopes are harbored in its extracellular domain (amino acids 40–79). PRRSV binding to the host CD163 receptor is mediated by GP4, which also regulates viral assembly and release, and induces protective immune responses. Hence, GP4 is identified as a central target for PRRS vaccine development. In this review, GP4’s structural characteristics, genetic evolution and interaction mechanisms are summarized. Its roles in viral life cycle, virulence, immune evasion and potential applications are discussed, providing a theoretical reference for PRRSV control. Full article

Porcine circovirus 3 (PCV3) is an emerging swine pathogen associated with reproductive disorders, multisystemic inflammation, and other clinical syndromes. The capsid protein (Cap), the principal structural and immunogenic component, is an ideal antigen for serological detection. However, its poor solubility in prokaryotic expression systems limits diagnostic assay development. In this study, the N-terminal 32 amino acids of Cap were truncated, and the protein was expressed in a soluble form using the SHuffle T7 Express strain. An indirect enzyme-linked immunosorbent assay (ELISA) using purified soluble Cap as a coating antigen was established and optimized. The assay exhibited excellent specificity, with no cross-reactivity against other common swine pathogens, high sensitivity, and good repeatability, with intra- and inter-assay coefficients of variation below 10%. The cut-off value was determined, and testing of 144 porcine serum samples showed a 78.47% concordance rate with PCR, indicating good diagnostic performance. This Cap-based indirect ELISA provides a reliable, cost-effective, and high-throughput tool for large-scale serological surveillance and epidemiological monitoring of PCV3, supporting improved disease control strategies in pig populations. Full article

Porcine reproductive and respiratory syndrome (PRRS), caused by PRRSV, causes substantial economic losses in the swine industry. Because viral variability and host genetic complexity limit conventional control, identifying host genetic factors associated with PRRS resistance through genomic approaches is important for disease-resistant breeding. In this study, 699 pigs were immunized with a PRRSV vaccine, 135 were selected for PRRSV infection experiments, and 133 were retained for whole-genome resequencing after two-stage phenotypic screening based on post-immunization and post-infection profiles. Genome-wide selection-signal analysis identified 12 highly differentiated regions (F_st > 0.15), annotated to 11 candidate genes: NFXL1, NIPAL1, CHIC2, LOC100623351, LOC100513671, LOC100513484, CENPC, STAP1, UBA6, GNRHR, and LOC100512727. The original exploratory GWAS identified candidate association signals, including signals annotated to PYGM, NFXL1, KIAA1324L, and FLNC; after PC1/PC2 adjustment, NFXL1 retained exploratory support, and additional exploratory signals were observed. Public PRRSV-related transcriptomic datasets provided additional expression-level evidence, with NIPAL1 and PYGM showing increased expression in PRRSV-infected porcine alveolar macrophages. Functional enrichment and variant-level analyses supported the biological relevance of the prioritized candidate gene set, particularly the chromosome 8 NFXL1 region, where the A-C-G haplotype was more frequent in resistant pigs. These findings provide useful genetic clues for further validation and PRRS resistance breeding. Full article

The emergence of swine acute diarrhea syndrome coronavirus (SADS-CoV), an alpha-coronavirus that causes fatal enteric disease in neonatal piglets with mortality rates up to 90%, demonstrates that bat-origin coronavirus has expanded its host range to pigs. Although SADS-CoV exhibits significant pandemic potential and capacity for cross-species transmission, the replication mechanisms of SADS-CoV remain largely unexplored. Identifying host factors responsible for SADS-CoV replication and elucidating its underlying mechanisms is essential for advancing fundamental knowledge of coronavirus biology and developing antiviral therapies. Here, we identified PABPC1 as a novel interactor of the SADS-CoV nucleocapsid (N) protein. Overexpression of PABPC1 restricted SADS-CoV infection, whereas knockdown of PABPC1 enhanced viral replication. Further study indicated PABPC1 as a host restriction factor of SADS-CoV in a manner dependent on its PABC domain. Mechanistically, PABPC1 enhances the ubiquitination of the N protein, therefore facilitating its recognition by the cargo receptor TOLLIP for selective autophagic degradation. This study systematically analyzes the interaction of host factors and the SADS-CoV N protein and identifies PABPC1 as a host restriction factor that limits viral replication via TOLLIP-mediated selective autophagy degradation of the N protein. These findings expand our knowledge of the SADS-CoV replication mechanism and provide additional antiviral strategies for controlling SADS-CoV. Full article

Lawsonia intracellularis, the etiologic agent of porcine proliferative enteropathy (PPE), represents a growing challenge for modern swine production systems. The infection often occurs in a subclinical form and, together with limited awareness of its true production impact, may delay diagnosis and the timely adoption of control measures. In our opinion, this under-recognition of subclinical infection represents the greatest barrier to successful PPE control. Disease management is further complicated by frequent co-infections, limitations of currently available diagnostic tools, and the progressive reduction in routine antimicrobial use, which has revealed the true burden of PPE under commercial conditions. We therefore argue that vaccination should no longer be considered a stand-alone preventive measure, but rather the cornerstone of an integrated, farm-specific management strategy combining accurate diagnostic interpretation, optimized production flows, biosecurity, nutritional management, and continuous veterinary–farmer collaboration. Drawing on both published evidence and the long-term field experience of the authors, this Opinion discusses the key challenges limiting effective PPE control and proposes a practical framework to improve disease recognition, prevention, and sustainable management under commercial production conditions. Full article

The genus Orthopestivirus, within the family Flaviviridae, includes important pathogens such as classical swine fever virus (CSFV), bovine viral diarrhea virus types 1 and 2 (BVDV-1 and BVDV-2), and border disease virus (BDV). Although Costa Rica is endemic for BVDV, it remains officially free of CSFV and BDV, highlighting the need for reliable molecular tools for pestivirus surveillance and differential diagnosis in swine populations. This study validated a conventional broad-range in-house RT-PCR assay targeting the 5′ untranslated region (5′UTR) of pestiviruses, a genomic region that is highly conserved among members of the genus Orthopestivirus. A wide variety of PCR-based assays have been developed for pestivirus detection; however, many are designed specifically for the diagnosis of bovine pestiviruses, such as bovine viral diarrhea virus type 1 (BVDV-1), BVDV-2, and HoBi-like pestivirus (HoBiPeV) in cattle. In contrast, the assay described in this study was standardized and validated to detect multiple pestivirus species, thereby providing a useful tool for surveillance and diagnostic applications across different host species. A total of 66 reference samples were analyzed to determine diagnostic sensitivity and specificity, while analytical sensitivity, repeatability, reproducibility, and selectivity were also evaluated. Additionally, pestivirus surveillance was conducted from 2014 to 2025. The assay showed a limit of detection of 1.2 copies/µL for CSFV and 11.7 copies/µL for BVDV, with diagnostic sensitivity and specificity of 98% and 100%, respectively. A total of 1072 surveillance samples were tested, including 11 bovine and 1061 porcine samples. Two porcine samples collected in 2015 were positive for pestivirus and clustered within the BVDV-2a group, representing the first molecular detection of BVDV-2a in pigs in Costa Rica. Circulation of BVDV-1b in cattle was also confirmed. The assay demonstrated satisfactory performance as a broad-range pestivirus surveillance tool and may support differential diagnosis in CSFV-free countries when combined with sequencing confirmation for pestivirus species identification. Full article