Bovine parainfluenza virus type 3 (BPIV-3) is one of the major pathogens of the bovine respiratory disease complex (BRDC). BPIV-3 surveillance in China has been quite limited. In this study, we used PCR to test 302 cattle in China, and found that the positive rate was 4.64% and the herd-level positive rate was 13.16%. Six BPIV-3C strains were isolated and confirmed by electron microscopy, and their titers were determined. Three were sequenced by next-generation sequencing (NGS). Phylogenetic analyses showed that all isolates were most closely related to strain NX49 from Ningxia; the genetic diversity of genotype C strains was lower than strains of genotypes A and B; the HN, P, and N genes were more suitable for genotyping and evolutionary analyses of BPIV-3. Protein variation analyses showed that all isolates had mutations at amino acid sites in the proteins HN, M, F, and L. Genetic recombination analyses provided evidence for homologous recombination of BPIV-3 of bovine origin. The virulence experiment indicated that strain Hubei-03 had the highest pathogenicity and could be used as a vaccine candidate. These findings apply an important basis for the precise control of BPIV-3 in China.
The global spread of lumpy skin disease (LSD), a devastating cattle disease caused by the lumpy skin disease virus (LSDV), is hampered by the lack of a practical small animal model for vaccine evaluation. Here, we established a mouse model by challenging C57BL/6 mice with goatpox virus (GTPV), a close relative of LSDV. Intranasal inoculation with a high dose (104.5 TCID50) of GTPV induced robust infection characterized by weight loss, fever, high viral loads in the lungs and livers, and significant pulmonary pathology including immune cell infiltration and alveolar wall thickening. Infected mice mounted potent humoral immunity, with rapid IgM and sustained IgG and GTPV-specific binding antibody responses. The infection also elicited a dynamic cellular immune response, marked by biphasic IFN-γ production and dose-dependent increases in IL-17A and TNF-α. This GTPV-based murine model effectively recapitulates critical aspects of LSDV pathogenesis and immunity, providing a valuable and accessible tool for the accelerated development and preclinical assessment of novel LSDV vaccines.