Bovine respiratory disease complex (BRDC) is a comprehensive disease in cattle caused by various viral and bacterial infections. Among them, bovine herpesvirus type I (BoHV−1) and bovine viral diarrhea virus (BVDV) play important roles and have caused huge financial losses for the cattle industry worldwide. At present, vaccines against BRDC include trivalent attenuated BoHV−1, BVDV−1, and BVDV−2 live vaccines, BoHV−1 live attenuated vaccines, and BoHV−1/BVDV bivalent live attenuated vaccines, which have limitations in terms of their safety and efficacy. To solve these problems, we optimized the codon of the BVDV−1 E2 gene, added the signal peptide sequence of the BoHV−1 gD gene, expressed double BVDV−1 E2 glycoproteins in tandem at the BoHV−1 gE gene site, and constructed a BoHV−1 genetics-engineered vectored vaccine with gE gene deletion, named BoHV−1 gE/E2−Linker−E2⁺ and BoHV−1 ΔgE. This study compared the protective effects in BoHV−1, BoHV−1 ΔgE, BoHV−1 gE/E2−Linker−E2⁺, and BVDV−1 inactivated antigen immunized guinea pigs and calves. The results showed that BoHV−1 gE/E2−Linker−E2⁺ could successfully induce guinea pigs and calves to produce specific neutralizing antibodies against BVDV−1. In addition, after BoHV−1 and BVDV−1 challenges, BoHV−1 gE/E2−Linker−E2⁺ can produce a specific neutralizing antibody response against BoHV−1 and BVDV−1 infections. Calves immunized with this type of virus can be distinguished as either vaccinated animals (gE^-) or naturally infected animals (gE⁺). In summary, our data suggest that BoHV−1 gE/E2−Linker−E2⁺ and BoHV−1 ΔgE have great potential to prevent BVDV−1 or BoHV−1 infection.

Bovine herpesvirus type I (BoHV-1) is an important pathogen that causes respiratory disease in bovines. The disease is prevalent worldwide, causing huge economic losses to the cattle industry. Gene-deficient vaccines with immunological markers to distinguish them from wild-type infections have become a mainstream in vaccine research and development. In order to knock out the gE gene BoHV-1, we employed the CRISPR/Cas9 system. Interesting phenomena were observed at the single guide RNA (sgRNA) splicing site, including gene insertion, gene deletion, and the inversion of 5′ and 3′ ends of the sgRNA splicing site. In addition to the deletion of the gE gene, the US9 gene, and the non-coding regions of gE and US9, it was found that the US4 sequence, US6 sequence, and part of the US7 sequence were inserted into the EGFP sgRNA splicing site and the 3′ end of the EGFP sequence was deleted. Similar to the BoHV-1 parent, the BoHV-1 mutants induced high neutralizing antibodies titer levels in mice. In summary, we developed a series of recombinant gE-deletion BoHV-1 samples using the CRISPR/Cas9 gene editing system. The mutant viruses with EGFP⁺ or EGFP⁻ will lay the foundation for research on BoHV-1 and vaccine development in the future.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a pathogen that causes severe abortions in sows and high piglet mortality, resulting in huge economic losses to the pig industry worldwide. The emerging and novel PRRSV isolates are clinically and biologically important, as there are likely recombination and pathogenic differences among PRRSV genomes. Furthermore, the NADC34-like strain has become a major epidemic strain in some parts of China, but the characterization and pathogenicity of the latest strain in Inner Mongolia have not been reported in detail. In this study, an NADC34-like strain (CHNMGKL1-2304) from Tongliao City, Inner Mongolia was successfully isolated and characterized, and confirmed the pathogenicity in pigs. The phylogenetic tree showed that this strain belonged to sublineage 1.5 and had high homology with the strain JS2021NADC34. There is no recombination between CHNMGKL1-2304 and any other domestic strains. Animal experiments show that the CHNMGKL1-2304 strain is moderately virulent to piglets, which show persistent fever, weight loss and high morbidity but no mortality. The presence of PRRSV nucleic acids was detected in both blood, tissues, nasal and fecal swabs. In addition, obvious pathological changes and positive signals were observed in lung, lymph node, liver and spleen tissues when subjected to hematoxylin–eosin (HE) staining and immunohistochemistry (IHC). This report can provide a basis for epidemiological investigations and subsequent studies of PRRSV.

Koumiss is a traditional fermented dairy product in Inner Mongolia pastoral areas, which is deeply loved by the local people; however, there has been little research on the characteristics of probiotics. This study comprehensively explored the properties of potential probiotics in koumiss, combining in vitro assays and whole-genome sequencing. The biochemical identification and phylogenetic tree results showed that the branches of this strain were close to Lacticaseibacillus paracasei, indicating that the strain was L. paracasei. The agar diffusion assay showed that the strain could effectively inhibit the growth of pathogenic bacteria. We have also identified the CHAP structural domain at the genomic level, which may be associated with the antibacterial activity of this strain. The strain was well tolerated in a simulated gastrointestinal environment, growing well at pH = 2.5, 0.3% bile salts, and 5% NaCl while exhibiting hydrophobicity, aggregation, and antioxidant properties. In vitro experiments and genome, levels showed that resistance (resistance genes) to the antibiotics used in this study was not present in this strain. In addition, we did not observe toxic effects in acute oral administration in mice, and no virulence genes were identified at the genomic level. Therefore, the strain has the potential for probiotic development.

Rabies virus causes fatal neurological disease, but the mechanisms by which its glycoprotein G influences neuronal dysfunction remain incompletely understood. In this study, we rescued two recombinant RABV LBNSE strains carrying G proteins from either the attenuated SAD-B19 strain or the virulent CVS11 strain, designated as rLBNSE-SfG and rLBNSE-CfG, respectively. Infection of primary mouse neurons and challenge experiments in mice showed that rLBNSE-CfG was associated with increased early neuronal infectivity and greater neurovirulence after intracerebral (i.c.) injection. Western blot analysis revealed that the SAD-B19-derived G protein exhibited a higher apparent molecular weight than the CVS11-derived G protein. Bioinformatic analysis identified strain-specific differences in putative post-translational modification sites, which may contribute to the observed migration difference. Quantitative proteomic analysis of mouse brain tissue showed that proteins downregulated in the rLBNSE-CfG group were enriched in synaptic vesicle cycle-related pathways and synapse-associated Gene Ontology (GO) terms. Integrated analysis identified a SNARE-associated module containing Snap25, Stx1a, and Vamp2, among which Vamp2 was significantly reduced in the rLBNSE-CfG group. In primary neurons, reduced Vamp2 abundance was associated with the extracellular domain of CVS11 G protein. These findings associate CVS11-derived G protein variation with reduced Vamp2 abundance and a presynaptic vesicle-related proteomic signature, although whether these molecular alterations directly impair synaptic vesicle release remains to be determined.