Aug 2026· Journal of Zhejiang University SCIENCE B· Vol 27, pp. 923 - 926· 0 citations· 16 references
Medicine
TL;DR
Young pigs are more susceptible to PRV and the infection in piglets is nearly 100% fatal, whereas adult pigs exhibit reproductive disorders such as abortion, stillbirths, and reduced fertility, ultimately decreasing farm productivity.
Abstract
Pseudorabies virus (PRV), known as porcine herpesvirus type I, belongs to the α-herpesvirus subfamily of the herpesviridae family. Its virions are oval or round, with a genome of approximately 143 000 bp and a high guanine-cytosine (GC) content of 73% (Pomeranz et al., 2005). While swine are the natural host and the virus has caused significant economic loss to the pig industry, PRV can infect other mammals, causing acute infectious diseases characterized by neurological symptoms (He et al., 2019; Cheng et al., 2020). Young pigs are more susceptible to PRV and the infection in piglets is nearly 100% fatal, whereas adult pigs exhibit reproductive disorders such as abortion, stillbirths, and reduced fertility, ultimately decreasing farm productivity (Zuckermann, 2000). Due to its global impact, PRV is classified as a Class B infectious disease by the World Organization for Animal Health (WOAH).
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.
Tao Liu, Xiuwen Zhang, Qingan Han et al.· Animals· 0 citations
Porcine parvoviruses (PPVs) are globally recognized as significant contributors to reproductive failure in swine, primarily due to their association with fetal death. Infection in pregnant sows can lead to severe reproductive disorders including stillbirth, mummification, embryonic death and infertility. A recombinase polymerase amplification assay targeting the variable region of the outer capsid protein gene of the PPV-7 genome was developed and systematically optimized under a range of reaction conditions. The assay showed optimal amplification at a constant temperature of 35.00 ˚C for 25 min, using 0.72 µM of each forward and reverse primer and 14.00 mM magnesium acetate. It demonstrated high sensitivity, reliably detecting as few as 2,050 copies of viral nucleic acids in both the conventional and fluorescent dye-based formats. The assay also showed high specificity, exhibiting no cross-reactivity with other common porcine pathogens such as porcine sapelovirus, porcine circovirus and classical swine fever virus. Of the 167 field samples tested, 23 were positive for PPV-7, corresponding to a positivity rate of 13.77%. Operating at a low and constant temperature, the assay eliminates the need for advanced laboratory equipment, making it highly suitable for pen-side application in field settings. In conclusion, this novel assay demonstrated strong potential for field-based detection of PPV-7 circulating within the swine population of Haryana, India, marking the first report of its kind from this region. Further validation using samples from clinically affected herds will strengthen its diagnostic applicability.
Niharika Chahal, S. Maan, K. Batra et al.· Veterinary Research Forum· 0 citations
This research presents a comprehensive analysis of the genetic landscape of prevalent NDV strains in Bangladesh between 2010 and 2024 using full‐length coding sequences of the fusion (F) gene and unraveled considerable genetic divergence.
Farah Zereen, Md. Abdur Rahman, M. Hossain et al.· Veterinary Medicine Internat...· 0 citations
Porcine reproductive and respiratory syndrome (PRRS) causes severe reproductive losses in pregnant sows and piglets, resulting in substantial economic impact on the swine industry worldwide. However, due to the significant genetic diversity and rapid evolutionary changes of the pathogen, continuous surveillance and detailed genetic analysis of circulating strains are essential. The current study aimed to evaluate the genetic diversity of the hypervariable (HV) region of non-structural protein 2 (nsp2) among North American PRRSV strains isolated from swine farms in Vietnam. Phylogenetic analysis and multiple sequence alignment were conducted to determine subtype classification and assess genetic variability. A total of 48 field isolates were obtained, of which 12.5% belonged to classical NA-PRRSV, 16.6% to NADC30-like and 70.9% to HP-PRRSV, primarily distributed across sublineages 1.4, 5.1, 8.7 and 8.9. Amino acid comparisons found multiple insertions, deletions and substitutions at various positions within the hypervariable region of nsp2. The study revealed substantial genetic variation in the HV region of nsp2 among NA-PRRSV field strains, largely associated with recombination and immune escape. These findings highlight epidemiological risks to vaccine efficacy and underscore the need for continuous molecular surveillance to support effective PRRSV control in Vietnam.
T. Le-thi, Van-Anh Huynh-Nguyen, Tram-Anh Bui-Nguyen et al.· Acta Veterinaria Hungarica· 0 citations
Porcine epidemic diarrhea virus (PEDV) poses a significant threat to the swine industry, and distinguishing circulating field strains from vaccine strains under field conditions remains challenging. In this study, we established a one-tube visual detection platform based on recombinase‑aided amplification (RAA) and PfAgo nuclease for simultaneous detection of the highly conserved N gene and the virulence‑associated ORF3 gene of PEDV. The assay completes within 60min, with a sensitivity of 100 cDNA copies/μL. Specificity tests showed no cross‑reactivity with other porcine viruses tested. Using FAM‑ and ROX‑labeled probes, the N gene produces green fluorescence, ORF3 generated red fluorescence, and dual positivity appears yellow, which all visible to the naked eye under blue light. In validation with 36 clinical samples, 12 were identified as PEDV‑positive, including 3 field strains. Using RT‑PCR sequencing as the reference, the method achieved 100% specificity. Overall, this RAA‑PfAgo approach integrates rapidity, high sensitivity, specificity, and visualization without complex instrumentation, offering a powerful tool for on‑site clinical diagnosis, strain differentiation, and epidemiological monitoring in pig farms.
Tao Wang, Jia-Qi Zhang, Hong-Bo Cui et al.· Journal of Virological Metho...· 0 citations
Feline calicivirus (FCV) is a highly heterogeneous pathogen and a major cause of feline upper respiratory tract disease, highlighting the need for continuous surveillance of its genetic diversity and pathogenic characteristics. In this study, we isolated and comprehensively characterized a newly isolated FCV strain, HN/ZZ/2025, from cats at a feline trading market in Zhengzhou, China, and systematically evaluated its molecular features, in vitro replication characteristics, physicochemical properties, and pathogenicity in cats. Phylogenetic analysis classified HN/ZZ/2025 as genotype GI. The isolate replicated efficiently in CRFK, F81, and Fc3Tg cells, reaching peak titers of 107.18, 107.50, and 105.89 TCID50/0.1 mL, respectively, and exhibited typical calicivirus-like particles with diameters of 35–40 nm. Complete genome analysis showed that HN/ZZ/2025 shared the highest nucleotide and amino acid sequence identities of 85.7% and 62.8%, respectively, with the closely related Chinese FCV strain CH-JL4, and revealed distinct amino acid variations within the hypervariable E region of the VP1 capsid protein. Experimental infection of cats (n = 3/group) resulted in pyrexia, with rectal temperatures reaching 39.8–40.2 °C, weight loss, oral ulceration, and persistent viral RNA shedding from 1 to 21 days post-infection. Viral RNA and VP1 antigen were detected in the lungs, trachea, kidneys, and spleen, indicating systemic dissemination and broad tissue distribution. Although no mortality occurred during the observation period, the observed clinical signs, viral dissemination, and histopathological lesions indicate that HN/ZZ/2025 is capable of causing clinically evident disease in experimentally infected cats. These findings provide useful insights into the molecular epidemiology, tissue tropism, and host–virus interactions of circulating FCV strains and establish HN/ZZ/2025 as a useful isolate for future studies of FCV genetic diversity and pathogenesis.
Jia-You Xing, Wen-Jie Xu, Zi-Xuan Fu et al.· Microorganisms· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
