The Japanese encephalitis virus (JEV), a causative agent of severe viral encephalitis in humans, has a biological cycle fluctuating between transmission in mosquitoes and avian species and amplification in pigs. Contact transmission of JEV was recently shown in pigs in the absence of arthropod vectors. Here, we show JEV transmission between infected and contact mice and further demonstrate that JEV transmission occurs between animals via aerosols, as both viral RNA and infectious JEV were detected in direct contact- and aerosol-exposed contact animals. The results of this study change our understanding of JEV transmission in densely populated regions and may help to explain JEV outbreaks without the presence of arthropod vectors.

Oncolytic viral therapy is a promising treatment approach for a variety of tumor forms. Although a number of studies have demonstrated that the pseudorabies virus (PRV) may be applied as an oncolytic carrier, the anti-colorectal cancer impact of the virus and the mechanism of its cytotoxic effect remain elusive. In this study, the replication capacity and cell activity of PRV attenuated live vaccines Bartha K61 and HB98 in HCT-8 cells in vitro were investigated. Next, the antitumor ability and safety were evaluated in a mouse model of HCT-8 tumor transplantation. Both PRV strains were able to suppress tumor growth and HB98 showed higher safety and efficiency than the Bartha K61 strain. Finally, flow cytometry and immunohistochemistry examination were performed to investigate its possible cytotoxic mechanism. The results showed that PRV inhibited tumor proliferation both in vitro and in vivo by inducing apoptosis. In summary, our study discovered for the first time that the live attenuated PRV has an oncolytic effect on HCT-8 cells with high efficacy and safety.

Bovine viral diarrhea virus (BVDV) infection causes subclinical to severe acute disease in cattle all over the world. Two genotypes of BVDV are recognized, BVDV1 and BVDV2. Currently, the subtypes of BVDV1b and BVDV2a are mainly circulating in China. Here, a newly noncytopathic (ncp) BVDV strain named BVDVNM21 was isolated and identified from cattle. We determined the complete genome sequence of BVDVNM21, phylogenetic analysis of 5 untranslated region (5UTR), N^pro, and E2 gene, and complete genome showed the virus belongs to BVDV2b subtype and formed an independent clade within BVDV2b. Genome-wide sequence analysis showed that BVDVNM21 had high homology with SD1301 (98.10) isolated from China. In the experimental infection study of guinea pigs and calves, they all developed similar clinical signs, including a pronounced and prolonged febrile response lasting more than 3 days and pronounced reduction in white blood cells (WBC) and platelets of more than 40. Moreover, guinea pigs showed more acute infection characteristics after infection, and WBC decreased by more than 50 at 1day postinfection (dpi), and they recovered in less than 3 days. The results indicated that the BVDVNM21 strain showed high virulence in calves. It was the first confirmed isolation of a highly pathogenic ncpBVDV2b in cattle, as well as the establishment of the BVDV-guinea pig model. This study may provide a basis for further research and control of the prevalence of BVDV2b in China.

Bovine enterovirus (BEV) is associated with respiratory, intestinal, and reproductive disorders in cattle, but its evolutionary characteristics and pathogenic potential remain insufficiently understood. In this study, a BEV strain was successfully isolated from a diarrheic fecal sample collected from an 8‐month‐old Holstein calf and was designated BEV NM2407. The virus replicated stably in Madin‐Darby bovine kidney (MDBK) cells, reaching a titer of 10 ^9.3 TCID ₅₀ /mL. Its complete genome was 7414 nt in length, and phylogenetic analysis classified the isolate as EV‐E4. Recombination analysis identified two putative breakpoints at 1950 and 5850 nt, and the resulting genomic regions showed the highest similarity to EV‐C‐ and EV‐D‐related reference lineages. VP1 analysis revealed a relatively conserved β ‐barrel core, whereas the major variations were concentrated in the surface‐exposed BC, DE, and GH loops. Experimental infection showed that BEV NM2407 was able to infect calves and induce mild clinical signs. Viral RNA was detected in nasal and rectal swabs as well as multiple tissues, with relatively higher levels in the trachea, lung, cecum, and rectum. Gross pathological changes were mainly characterized by intestinal hyperemia/congestion, most prominently in the jejunum. Histopathological examination revealed epithelial necrosis in the jejunum and rectum, together with lymphocyte depletion and necrosis in ileal lymphoid follicles. Overall, BEV NM2407 demonstrated infectivity in calves under experimental conditions. The observed viral shedding, tissue distribution, and localized pathological lesions provide further evidence of the pathogenic potential of BEV, expand current understanding of its molecular evolution and biological characteristics, and provide a basis for further investigations into the pathogenesis of BEV infection in cattle.