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Background: Pseudorabies (PR) (also called Aujeszky's disease, AD) is a serious infectious disease affecting pigs and other animals worldwide. The emergence of variant strains of pseudorabies virus (PRV) since 2011 has led to PR outbreaks in China and a vaccine that antigenically more closely matches these PRV variants could represent an added value to control these infections. Methods: The objective of this study was to develop new live attenuated and subunit vaccines against PRV variant strains. Genomic alterations of vaccine strains were based on the highly virulent SD-2017 mutant strain and gene-deleted strains SD-2017ΔgE/gI and SD-2017ΔgE/gI/TK, which constructed using homologous recombination technology. PRV gB-DCpep (Dendritic cells targeting peptide) and PorB (the outer membrane pore proteins of N. meningitidis) proteins containing gp67 protein secretion signal peptide were expressed using the baculovirus system for the preparation of subunit vaccines. We used experimental animal rabbits to test immunogenicity to evaluate the effect of the newly constructed PR vaccines. Results: Compared with the PRV-gB subunit vaccine and SD-2017ΔgE/gI inactivated vaccines, rabbits (n = 10) that were intramuscularly vaccinated with SD-2017ΔgE/gI/TK live attenuated vaccine and PRV-gB + PorB subunit vaccine showed significantly higher anti-PRV-specific antibodies as well as neutralizing antibodies and IFN-γ levels in serum. In addition, the SD-2017ΔgE/gI/TK live attenuated vaccine and PRV-gB + PorB subunit vaccine protected (90–100%) rabbits against homologous infection by the PRV variant strain. No obvious pathological damage was observed in these vaccinated rabbits. Conclusions: The SD-2017ΔgE/gI/TK live attenuated vaccine provided 100% protection against PRV variant challenge. Interestingly, the subunit vaccines with gB protein linked to DCpep and PorB protein as adjuvant may also be a promising and effective PRV variant vaccine candidate. [ABSTRACT FROM AUTHOR]

Porcine pseudorabies has long existed in China and is a serious threat to the Chinese farming industry. To understand the prevalence and genetic variation of the porcine pseudorabies virus (PRV) and its pathogenicity in Yunnan Province, China, we collected 560 serum samples across seven Yunnan Province regions from 2020 to 2021 and detected anti-gE antibodies in these samples. Sixty-one clinical tissue samples were also collected from pigs with suspected PRV that were vaccinated with Bartha-K61. PRV-gE antibodies were found in 29.6% (166/560) of the serum samples. The PRV positivity rate in clinical tissue samples was 13.1% (8/61). Two isolates, PRV-KM and PRV-QJ, were obtained. The identity of the gB, gD, and gE genes between these isolates and the Chinese mutants exceeded 99.5%. These isolates and the classical Fa strain were used to infect 4-week-old rats intranasally to assess their pathogenicity. All infected rats showed the typical clinical and pathological features of PRV two days post-infection. The viral loads in the organs differed significantly among the infected groups. Viruses were detected in the saliva and feces at 12 h. Significant dynamic changes in total white blood cell counts (WBC), lymphocyte counts (Lym), and neutrophil counts (Gran) occurred in the blood of the infected groups at 24 and 48 h. These results show that mutant PRV strains are prevalent in Bartha-K61-vaccinated pigs in Yunnan Province, China. Moreover, rats shed PRV in their saliva and feces during early infection, indicating the need for rodent control in combatting PRV infections in Yunnan Province, China.

Sonchus ( Sonchus oleraceus ) originated from Europe and is now cultivated worldwide. The wild resources of sonchus are very abundant, and it has rich nutritional and medicinal value. In this study, 15 sonchus samples with typical symptoms showing leaf curling, vein thickening, and enations were collected from Guigang and Baise City of Guangxi, China. Diseased sonchus were identified by PCR detection, whole genome sequence amplification, and phylogenetic and recombination analysis. The results showed that all the samples were confirmed infected by begomoviruses, and three full-length viral genomes were obtained from 15 sonchus, named GG7-13, GG8-6, and BS63-5. The full genome lengths were 2,584, 2,735, and 2,746 nt, respectively. The nucleotide identities among the three isolates ranged from 92.67 to 99.93%. All of them shared the highest identities (greater than 91.69%) with other isolates of ageratum yellow vein China virus (AYVCNV) (available on GenBank). According to the guidelines of classification of begomoviruses, the virus isolates obtained in this study are different isolates of AYVCNV; a phylogenetic tree analysis showed that these isolates formed a large branch with three other Guangxi isolates of AYVCNV, indicating their close evolution. The genome structures of GG8-6 and BS63-5 are consistent with the monopartite genome virus of the begomoviruses, and both have six open reading frames (ORFs), while GG7-13 has a 151-nt deletion between C2 and C3, resulting in a mutant strain of only five ORFs. This study is the first report on S. oleraceus infected by ageratum yellow vein China virus., Competing Interests: The author(s) declare no conflict of interest.