Search Results (68)

Porcine reproductive and respiratory syndrome (PRRS) represents a critical infectious disease caused by the PRRS virus (PRRSV), posing a substantial threat to the global swine industry. In China, there is currently an epidemic trend characterized by the coexistence of multiple evolving genotypes. Effective prevention and control measures are contingent upon the availability of rapid, precise, and sensitive pathogen detection technologies. Addressing the need for swift differentiation of the predominant circulating strains, including the classical strains (PRRSV-C), the highly pathogenic strains (PRRSV-HP), and NADC30-like strains (PRRSV-NA), this study focuses on the NSP2 region of each lineage. It establishes a triple TaqMan-qPCR method capable of simultaneously genotyping these three lineages. The method demonstrated no cross-reactivity with other viruses, including porcine parvovirus (PPV), porcine transmissible gastroenteritis virus (TGEV), porcine pseudorabies virus (PRV), classical swine fever virus (CFSV), African swine fever virus (ASFV), porcine epidemic diarrhea virus (PEDV), porcine rotavirus (RV), and porcine circovirus (PCV2), thereby fully affirming its specificity. The sensitivity analysis demonstrated that the limit of detection (LOD) for the NSP2 gene in each lineage was 1 copy/μL based on the purified plasmids. Both inter-group and intra-group coefficients of variation (CV) were less than 4%, indicating high reproducibility. Comparative studies with commercial kits revealed that the developed TaqMan-qPCR method exhibited 100% relative sensitivity and a relative conformity rate exceeding 98%, suggesting its potential as a viable alternative to commercial kits. Furthermore, the analysis of 1049 clinical samples using the qPCR method indicated that the PRRSV-NADC30-like strains are currently the predominant circulating strain in clinical settings in Hebei Province. In conclusion, this study developed a triple TaqMan-qPCR method capable of simultaneously identifying PRRSV-C, PRRSV-HP and PRRSV-NA, enabling rapid and accurate identification of the PRRSV genotypes prevalent in pig populations. This provides a robust technical tool for the development of targeted immunization and prevention strategies. Full article

Under a One Health framework, viruses of veterinary and zoonotic importance pose significant threats to animal and human health, food security, and livelihoods, particularly in regions with intense human–animal interactions. In West Africa, despite recent advances in surveillance programs, important gaps remain in understanding viral diversity and cross-species transmission at wildlife–livestock interfaces. We conducted metagenomic surveillance to characterize viruses circulating across livestock, domestic animals, and wildlife in rural Ghana in 165 animals sampled across five regions. Viral RNA from serum and tissue samples was sequenced with the Illumina platform, and genomes were de novo assembled with MEGAHIT. Phylogenetic relationships were reconstructed using Bayesian approaches. We report the first genomic sequences of porcine parvovirus 3, canine parvovirus, rotavirus A genotype R16, and bovine hepacivirus subtype B from Ghana in over a decade. Phylogenetic analyses revealed intercontinental linkages between Africa and Europe for parvoviruses, persistence of hepacivirus lineages, and evidence of cross-species transmission for rotavirus. Notably, detection in apparently healthy animals highlights underrecognized circulation, gaps in vaccination effectiveness, trade-related biosecurity vulnerabilities, and the role of wildlife in viral maintenance and transmission. Our findings reveal dynamic viral diversity and connectivity across animal populations and ecological interfaces, emphasizing the fluid and interconnected nature of pathogen circulation within One Health systems. By integrating metagenomics and phylogenetics, this study provides a scalable framework for enhancing surveillance capacity, enabling the early detection of emerging threats and informing targeted strategies to mitigate zoonotic and economically important viral diseases in West Africa. Full article

PPV5 NS1 is a nonstructural and multifunctional protein comprising helicase and nuclease domains. The helicase domain contains conserved motifs from superfamily 3 helicases, including Walker A, Walker B, Motif B’, Motif C, and Box VII, whereas the nuclease domain consists of glutamate, a HUH motif, lysine, and tyrosine. In Mexico, the reported prevalence of PPV5 is higher than in other countries, with notable amino acid differences compared with pathogenic PPVs. This study compares the helicase and nuclease domains from a full-length PPV5 NS1 sequence with porcine parvovirus 1 (PPV1) and canine parvovirus (CPV) to characterize the protein further and perform three-dimensional (3D) modeling using bioinformatic tools, including solvent-accessible surface area (SASA) and electrostatic potential assessments. The main findings highlight the ATP-binding pocket, showing electrostatic values in PPV5 that contrast with PPV1 and CPV. The electrostatic potential 3D models suggest those differences involve non-conserved regions. In particular, the PPV5 Box VII surface is predominantly negative due to a glutamate substitution at position 7. In the nuclease domain, the interaction with Mg²⁺ differs between PPV5 and pathogenic PPV. The electrostatic findings suggest that these differences may have functional implications for both domains, but confirmation must be completed with functional assays. Full article

Live virus inoculation (LVI) is widely used for porcine reproductive and respiratory syndrome virus (PRRSV) stabilization, yet preparation practices and pathogen composition remain poorly characterized. This study aimed to evaluate variability in LVI preparation, quantify PRRSV genomic load, and detect additional swine pathogens. A survey was conducted to document LVI preparation methods, and samples were analyzed using reverse-transcription quantitative PCR (RT-qPCR) for PRRSV quantification and next-generation sequencing for PRRSV and the metagenomic characterization of additional pathogens. Among 61 LVI samples, substantial variability was observed in preparation practices and viral composition, with 31 distinct PRRSV variants identified and seven samples containing multiple strains. PRRSV RNA concentrations ranged from 10^1.69 to 2.52 × 10⁸ copies/mL. Metagenomic analysis detected a complete or near-complete genome for PRRSV, porcine parvovirus, and porcine circovirus type 2. Genome fragments of porcine sapovirus, porcine rotavirus, porcine astrovirus, and bacterial genetic material from Salmonella spp., Pseudomonas spp., Streptococcus spp., and Escherichia coli were also detected. These findings highlight substantial heterogeneity in LVI materials and encourage the use of next-generation sequencing to verify LVI PRRSV composition and screen for co-existing pathogens, reinforcing the need for standardized preparation protocols and further investigation into optimal viral dosing for effective immunization. Full article

The distribution and genetic diversity of economically significant pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), porcine circovirus type 3 (PCV3), and porcine parvovirus 1 (PPV1), across extensive Russian territory within wild boars that serve as reservoirs remain poorly characterized. This study aimed to conduct a molecular epidemiological survey of these viruses in wild boar populations. The samples of 476 wild boars, collected across Russia between 2021 and 2025, were tested by PCR for the detection of viral genomes. While PRRSV was not detected, we found high detection rates for PCV2 (34.9%), PCV3 (35.5%), and PPV1 (25.4%). For PCV2, the co-circulation of two genotypes, PCV2b (5/53) and PCV2d (48/53), was observed. All 29 PCV3 sequences belonged to the PCV3a genotype. For PPV1, the presence of the PPV1a, PPV1b, and PPV1d genotype, as well as unclassified isolates, was shown. Co-infection of different viruses was detected: PCV2/PCV3 (16.0%), PCV2/PPV1 (6.9%), PCV2/PCV3/PPV1 (6.9%), and PCV3/PPV1 (4.4%). This is the first comprehensive study that demonstrates the wide dissemination and genetic diversity of PCV2, PCV3, and PPV1 within the wild boar population in Russia and highlights their role as a potential reservoir in viral evolution and spread. Full article

The global swine industry suffers persistent economic losses and health challenges due to major viral pathogens such as African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), and porcine circovirus (PCV). Traditional diagnostic methods, including virus isolation, serology, and quantitative PCR (qPCR), are limited by time, equipment requirements, and field applicability. Recent advances in CRISPR-based diagnostics, particularly those leveraging the collateral cleavage activity of Cas12a and Cas13a, have enabled rapid, sensitive, and field-deployable nucleic acid detection. This review outlines the principles of CRISPR-Cas12a/13a systems, their integration with isothermal amplification techniques, and their application in detecting major swine viruses. Cas12a-based platforms (e.g., DETECTR) and Cas13a-based systems (e.g., SHERLOCK) achieve detection limits as low as single-copy/μL within 25–60 min at 37 °C, offering high specificity and compatibility with visual readouts. Applications include ASFV, PRRSV, CSFV, PCV, foot-and-mouth disease virus (FMDV), porcine rotavirus (PoRV), and porcine parvovirus 7 (PPV7). Despite significant advances, challenges remain, notably the reliance on nucleic acid extraction and the need for fully integrated “sample-in, result-out” systems. Ongoing innovations in extraction-free methods, lyophilized reagents, and multiplex detection will strengthen the role of CRISPR diagnostics in swine disease surveillance and control. From an application standpoint, the technology offers a low-capital, field-adaptable alternative to qPCR, with its value proposition rooted in early outbreak containment and loss prevention. Its adoption pathway is expected to vary across production systems—serving as a sentinel tool in intensive settings, a leapfrogging solution in rapidly intensifying regions, and through shared-service models in resource-limited contexts. However, translation to routine use still requires overcoming standardization hurdles, regulatory validation, and workflow integration. Full article

Heat is widely used to decontaminate livestock environments, yet performance varies with virus, surface, moisture, and organic load. We evaluated the effects of temperature (50, 60, 70 °C) and exposure time on the viability of 10 veterinary-relevant viruses (or surrogates) placed on four nonporous surfaces (plastic, rubber, aluminum, stainless steel) under dry or wet conditions, and in organic matrices (blood, wheat straw, complete feed). Infectivity was quantified by TCID₅₀ using independent duplicate experiments with duplicate titrations. Moist heat consistently outperformed dry heat: at 60–70 °C, all enveloped viruses, and most non-enveloped viruses were inactivated on surfaces within 5 min, while porcine parvovirus (PPV) remained the outlier, requiring ≥60 min. In contrast, dry heat allowed several viruses to persist for 24 h at 70 °C, underscoring that temperature alone is an unreliable predictor of rapid decontamination in the absence of humidity. Organic matrices modulated outcomes in a substrate- and virus-dependent manner, with some combinations accelerating inactivation and others prolonging survival to ≥180 min at ≥60 °C. These findings support matrix-aware, heat-assisted protocols for facilities and transport (e.g., 70 °C for ≥10 min under high humidity for most enveloped viruses), while recognizing exceptions such as PPV. The data provide actionable parameters to optimize thermo-assisted decontamination in veterinary systems. Full article

Cell cultures are an essential tool for laboratory diagnosis of porcine viral infections. However, interpreting the results requires considering the species and tissue origin of cell lines as well as the specific virus replication characteristics (cytopathic effect). This guide discusses the development of techniques for the primary isolation of viruses from biological material and provides recommendations for culturing viruses in different cell types. According to the World Organization for Animal Health, laboratory diagnosis should aim to isolate the virus in cell culture. We have studied the evolution of virus isolation methods for various diseases affecting pigs, including African swine fever virus (ASFV), classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), pseudorabies virus (Aujeszky’s disease, PRV), rotaviruses (RV), teschoviruses (PTVs), swine pox virus (SwPV), swine influenza A virus (IAVs), parvovirus (PPV), coronaviruses, circoviruses (PCVs), diseases with vesicular syndrome, and others. During our analysis of the literature and our own experience, we found that the porcine kidney (PK-15) cell line is the most suitable for isolating most viral porcine pathogens. For ASFV and PRRSV, the porcine alveolar macrophages (PAMs) continue to remain the primary model for isolation. These findings can serve as a starting point for virological reference laboratories to select optimal conditions for cultivating, obtaining field isolates, and strain adaptation. Full article

Virus inactivation exhibits varying disinfection kinetics due to structural or genomic differences. Standard post-disinfection assessment relies on observing cytopathic effects in inoculated cell cultures, which are limited by sensitivity, availability, cost, and turnaround time. This study explores nucleic acid aptamers as molecular sensors to differentiate between intact and post-disinfection virus particles. To discover aptamers, 12 cycles of an automated SELEX (Systematic Evolution of Ligands by Exponential Enrichment) experiment were performed using recombinant (r)-VP2 protein of canine parvovirus (CPV). Enrichment of single stranded (ss) DNA binders was evaluated by sequencing the enriched libraries. The most abundant sequences were tested for binding with coated rVP2 and CPV (intact and treated with heat and peracetic acid (PAA) disinfectant) followed by detection using PCR. Binding specificity was assessed using intact and heat-treated feline panleukopenia virus (FPV) and porcine parvovirus (PPV). Sequencing of the DNA libraries from selection cycle 6 and cycle 12 products showed individual sequence enrichment with maximum frequencies of 2.14% and 8.65%, respectively. The top three abundant sequences from each cycle confirmed rVP2 binding. In the case of CPV, only heat-treated and PAA-treated CPV showed binding to the candidate sequences. However, reduced binding to the CPV-specific antibody was observed for rVP2 and treated CPV compared to intact CPV. No apparent binding of the tested sequences was observed for FPV and PPV. Aptamers binding to denatured but not intact CPV demonstrate the potential to distinguish between the two states, providing a basis for developing a molecular assay to assess disinfection efficacy. Full article

Porcine parvovirus (PPV), a non-envelope single-stranded DNA virus, causes severe reproductive disorders in swine worldwide, characterized by fetal mortality, mummification, and reduced boar fertility. As a highly prevalent pathogen in Chinese swine herds, PPV imposes substantial economic burdens on intensive pig production systems. This review systematically synthesizes recent advances in PPV virology, focusing on genomic evolution of emerging strains (PPV1–PPV8), epidemiological dynamics of emerging strains, molecular pathogenesis, and novel diagnostic tools. Furthermore, we critically evaluate current vaccine strategies, highlighting their limitations in cross-protective efficacy and viral shedding control. By integrating multi-omics insights with immunological profiling, this work delineates actionable pathways for next-generation vaccine design and proposes a roadmap for rational antigen selection. This review consolidates foundational knowledge and establishes a translational bridge between basic virology and prevention and control of porcine parvovirus, addressing critical gaps in porcine reproductive disease management. Full article

Xenotransplantation using pig cells, tissues, or organs is advancing toward clinical application to address the shortage of human donor organs for treating organ failure. However, this emerging technology carries the risk of transmitting pathogenic porcine microorganisms, particularly viruses. The recent transmission of a porcine herpesvirus to the first human recipient of a pig heart highlights the urgent need for more rigorous screening of donor pigs. To identify potentially pathogenic porcine viruses, highly sensitive and specific detection methods are required. PCR-based techniques able to detect porcine cytomegalovirus/porcine roseolovirus (PCMV/PRV), hepatitis E virus (HEV), porcine circoviruses (PCV1-4), porcine lymphotropic herpesviruses (PLHV-1-3), porcine endogenous retroviruses (PERVs), porcine parvovirus (PPV), Torque teno sus viruses (TTSuV1,2), atypical porcine pestivirus (APPV) and SARS-CoV-2 were established. Immunological assays that detect antibodies as indirect indicators of infection were established for PCMV/PRV, HEV, PLHVs and PERVs. Since most veterinary laboratories focus on detecting viruses that are pathogenic to pigs and cause economic losses to the swine industry, screening for viruses relevant to xenotransplantation should be conducted in specialized virological diagnostic units. In this context, we present a complete collection of the newest and detailed protocols for comprehensive viral screening, along with guidance on how to implement these methods effectively. Full article

Wild boars are recognized reservoirs of numerous viral pathogens, posing a significant risk to domestic pig populations, particularly in areas with poor biosecurity. This study assessed the prevalence and co-infection patterns of porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine cytomegalovirus (PCMV), African swine fever virus (ASFV), classical swine fever virus (CSFV), and pseudorabies virus (PRV) in wild boars from western Serbia and the Republic of Srpska (Bosnia and Herzegovina). Sixty-six spleen samples from legally hunted wild boars were analyzed by qPCR. All animals were negative for ASFV, CSFV, and PRV. The cumulative prevalence of infection with at least one of the other three viruses was 86.4% (95% CI: 76.2–92.8%). PCMV was detected in 74.2% of samples, PCV2 in 50%, and PPV in 28.8%. Co-infections were common: 42.4% of animals were positive for two viruses, and 12.1% for all three. A statistically significant association was observed between triple co-infection and sex, with higher rates in males. Subadult wild boars showed the highest PCV2 + PCMV co-infection rate (p = 0.0547). These findings highlight the need to expand molecular surveillance, particularly for PCMV, in both wild and domestic pigs, especially in regions reliant on low-biosecurity backyard farming. Full article

Porcine parvovirus 5 (PPV5) is a novel virus frequently detected in pigs worldwide. However, its identification and prevalence in domestic pigs in Russia have not been described. In this study, retrospectively, 984 serum samples collected between 2020 and 2023 were tested by qPCR. All samples were obtained from 20 pig farms located in 10 regions of Russia. PPV5 circulation was confirmed in 11 pig farms with the overall detection rate at 8.9%. The highest detection rate was estimated in the farms of the Belgorod Region (17.1%), followed by the Sverdlovsk Region (15.9%), the Republic of Buryatia (14.7%), and the Moscow Region (14.0%). It has been confirmed that PPV5 has been circulating in the swine population since at least 2021. The phylogenetic analysis revealed a high nucleotide identity of Russian isolates with strains from the USA, Colombia, and China. The Moscow-4060 strain was isolated in primary porcine testicular cells (PPTCs), and its continuous replication was confirmed by qPCR. During microscopy, cytoplasmic vacuolization, pyknosis, and other alterations were observed. The results demonstrate the evidence of PPV5 circulation in domestic pigs in Russia and the first isolation of the virus ever described. These findings serve as a first step for studying PPV5 in vivo. Full article

Porcine parvovirus 8 (PPV8), the most recently discovered PPV genotype, was first reported in pigs in Guangdong, China, in 2021. In this study, we assessed 69 lung tissue samples collected from animals with high fever or respiratory syndrome on pig farms in Guangxi in 2018. Five nearly full-length genome sequences were characterized and analyzed. The percentage of PPV8-positive samples was 13.04% (9/69), and five complete PPV8 sequences were obtained, which were designated PPV8-A, PPV-B, PPV8-G, PPV8-H, and PPV8-I. The genomic sequence homology among the five PPV8 strains and other PPVs was 25.91–98.84%, with the closest genetic relationship to PPV8-GDJM2021 (98.84%), followed by PPV1 (44.64%). For the NS1 protein, phylogenetic analysis revealed that the identified PPV8-I was closely related to PPV8-GDJM2021 and that PPV8-A was closely related to PPV8-H, whereas PPV8-B and PPV8-G were more distantly related to the other PPV8 strains. For the VP1 protein, phylogenetic analysis revealed a close correlation between PPV8-H and PPV8-GMJM2021, whereas PPV8-A, PPV8-B, PPV8-G, and PPV8-I were more distantly related. In conclusion, five nearly full-length sequences were amplified, and the molecular characteristics of PPV8 were analyzed. These findings improve our understanding of the PPV8 genome. Full article

Background/Objectives: The development of vaccines that elicit both T-cell and B-cell responses is crucial for effective immunity against pathogens. This study introduces a novel approach to identify precise epitope peptides within viral proteins that can stimulate both arms of the adaptive immune response, using Porcine Parvovirus (PPV) as a model. Methods: Mice were infected with PPV, and a peptide array was utilized to detect IgG signals in their sera. This approach facilitated the assessment of the immunogenicity of the PPV proteome, leading to the identification of 14 potential epitope candidates. These candidates were then used to immunize additional mice, and their ability to induce T-cell and B-cell responses was evaluated. Results: The immunization experiments identified an optimal peptide, P6, which robustly activated both T cells and B cells. Further analysis of the sub-regions of this peptide confirmed P6 as the most potent inducer of immune responses. The anticipated epitope was detected in mice immunized with P6, highlighting the efficacy of our method in identifying epitopes that engage both T cells and B cells. Conclusions: This study presents a novel strategy for the identification of dual T-cell and B-cell epitopes by directly evaluating the immunoreactivity of antibodies in serum. This finding holds significant promise for the advancement of epitope-based vaccines. Full article