Pseudorabies virus (PRV) variants were discovered in immunized pigs in Northern China and have become the dominant strains since 2011, which caused huge economic losses. In this study, a classical PRV strain was successfully isolated in a PRV gE positive swine farm. The complete genome sequence was obtained using a high-throughput sequencing method and the virus was named JS-2020. The nucleotide homology analysis and phylogenetic tree based on complete genome sequences or gC gene showed that the JS-2020 strain was relatively close to the classical Ea strain in genotype II clade. However, a large number of amino acid variations occurred in the JS-2020 strain compared with the Ea strain, including multiple immunogenic and virulence-related genes. In particular, the gE protein of JS-2020 was similar to earlier Chinese PRV strains without Aspartate insertion. However, the amino acid variations analysis based on major immunogenic and virulence-related genes showed that the JS-2020 strain was not only homologous with earlier PRV strains, but also with strains isolated in recent years. Moreover, the JS-2020 strain was identified as a recombinant between the GXGG-2016 and HLJ-2013 strains. The pathogenicity analysis proved that the PRV JS-2020 strain has typical neurogenic infections and a strong pathogenicity in mice. Together, a novel recombinant classical strain was isolated and characterized in the context of the PRV variant pandemic in China. This study provided some valuable information for the study of the evolution of PRV in China.

Viruses depend on the metabolic mechanisms of the host to support viral replication. We utilize an approach based on ultra-high-performance liquid chromatography/Q Exactive HF-X Hybrid Quadrupole-Orbitrap Mass (UHPLC-QE-MS) to analyze the metabolic changes in PK-15 cells induced by the infections of the pseudorabies virus (PRV) variant strain and Bartha K61 strain. Infections with PRV markedly changed lots of metabolites, when compared to the uninfected cell group. Additionally, most of the differentially expressed metabolites belonged to glycerophospholipid metabolism, sphingolipid metabolism, purine metabolism, and pyrimidine metabolism. Lipid metabolites account for the highest proportion (around 35%). The results suggest that those alterations may be in favor of virion formation and genome amplification to promote PRV replication. Different PRV strains showed similar results. An understanding of PRV-induced metabolic reprogramming will provide valuable information for further studies on PRV pathogenesis and the development of antiviral therapy strategies.

Background: Brucella abortus is the main causative agent for bovine brucellosis. B. abortus A19 is a widely used vaccine strain to protect cows from Brucella infection in China. However, A19 has a similar lipopolysaccharide (LPS) antigen to that of the field virulent Brucella strain, whose immunization interferes with the serodiagnosis of vaccinated and infected animals. [Aim] To develop a novel Brucella DIVA vaccine candidate. Study design and methods: The B. abortus mutant A19mut2 with the formyltransferase gene wbkC is replaced by an acetyltransferase gene wbdR from E. coli O157 using the bacterial homologous recombination technique, generating a modified O-polysaccharide that cannot induce antibodies in mice against wild-type Brucella LPS. The biological phenotypes of the A19mut2 were assessed using a growth curve analysis, agglutination tests, Western blotting, and stress resistance assays. Histopathological changes and bacterial colonization in the spleens of vaccinated mice were investigated to assess the residual virulence and protection of the A19mut2. Humoral and cellular immunity was evaluated by measuring the levels of IgG, IgG subtypes, and the release of cytokines IFN-γ and IL10 in the splenocytes of the vaccinated mice. ELISA coated with wild-type LPS can distinguish mouse antibodies induced by A19 and A19mut2 immunization. Results: The A19mut2 showed a decreased residual virulence in mice, compared to the A19 strain, but induced significant humoral and cellular immune responses, as the A19 immunization did. The protection efficacy of A19mut2 immunization against B. abortus S2308 Nal^R infection was similar to that of A19 immunization. Conclusion: The A19mut2 has potential as a novel DIVA vaccine candidate in the future.

Ziwuling black goat (ZBG) is the main breed of indigenous goat for meat, wool, and skin in northwest china. However, the population has faced a sharp decline in the past few decades, mainly due to the declining efficiency of goat farming, which has led to the reluctance of farmers to raise goats. Litter size (LS), horn or no horn (HN), wool color (WC), and body conformation (BC) traits are the four main economic indicators of goat culture, which have the potential to increase population growth rate. The aim of the study was to identify potential genomic regions associated with body conformation traits of ZBG using genome-wide association studies (GWAS), and to identify molecular markers that influence LS, HN, WC, and BC traits of goats for the improvement of genetic resources of goats. In the study, we used the Illumina sequencing platform to re-sequence the genomes of 318 ZBG (12 males and 306 females) belonging to natural populations in 4 different regions, including LS, HN, WC, body height (BH), body weight (BW), body diagonal length (BL), and chest circumference (CC). The GWAS were conducted to identify candidate genes with different phenotypes which laid a foundation for further studies on the biological functions of these genes. A total of 41 single nucleotide polymorphisms (SNPs) and 89 candidate genes were obtained in 7 phenotypes of goats. Among them, 5 SNPs and 18 genes were significantly associated with the LS traits in goats, and these loci were located on 2 chromosomes. There are 5 SNPs and 10 genes significantly associated with the HN traits, and these loci are located on 5 chromosomes. There were 18 SNPs and 31 genes significantly associated with the WC traits, and these loci were located on 16 chromosomes. There are 6 SNPs and 13 genes significantly associated with the BH traits, and these loci are located on 6 chromosomes. There are 2 SNPs and 7 genes were significantly associated with the BL traits, and these loci were located on 2 chromosomes. There are 2 SNPs and 2 genes significantly associated with the BW traits, and these loci are located on 2 chromosomes. There are 3 SNPs and 8 genes were significantly associated with the CC traits, and these loci were located on 3 chromosomes. We investigated the molecular genetic mechanism of LS, HN, WC, and BC traits of ZBG by analyzing its genome data. The study identified a series of SNPs and candidate genes associated with growth and reproductive traits, which helped accelerate the breeding process of goat breeds.

Since viral hemorrhagic septicemia virus (VHSV) was first identified in rainbow trout, it has evolved into four major genotypes in the process of infecting multiple hosts. The different levels of virulence among genotypes of VHSV are caused by genetic evolution. In this study, the complete genome sequences of global VHSV strains were obtained from the GenBank database and their genetic relationships were analyzed. The maximum likelihood (ML) phylogenetic tree based on the complete genomes of VHSV showed that globally, VHSV strains evolved into two region-specific clades, namely the European clade and the North American clade. North American VSHV strains are more conserved than European strains. Both European and North American strains are subjected to purifying selection. All VHSV proteins are gathered into their region-specific clusters in genetic distance space. Furthermore, North American and Asian strains have organized glycosylation sites in their G protein. An early Japanese strain, KRRV9822, which clusters into the North American clade, has undergone potential recombination. Together, the region-specific genetic relationship and mutation characteristics of global VHSV strains were revealed with a crucial perspective for epidemiological research on VHSV.