Genomic characterization and pathogenic study of two porcine reproductive and respiratory syndrome viruses with different virulence in Fujian, China

Two strains of porcine reproductive and respiratory syndrome virus (PRRSV) were isolated in 2006 and 2016 and designated as FZ06A and FZ16A, respectively. Inoculation experiments showed that FZ06A caused 100% morbidity and 60% mortality, while FZ16A caused 100% morbidity without death. By using genomic sequence and phylogenetic analyses, close relationships between a Chinese highly pathogenic PRRSV strain and the FZ06A and FZ16A strains were observed. Based on the achieved results, multiple genomic variations in Nsp2, a unique N-glycosylation site (N³³→K³³), and a K151 amino acid (AA) substitution for virulence in the GP5 of FZ16A were detected; except the 30 AA deletion in the Nsp2-coding region. Inoculation experiments were conducted and weaker virulence of FZ16A than FZ06A was observed. Based on our results, a 30 AA deletion in the Nsp2-coding region is an unreliable genomic indicator of a high virulence PRRSV strain. The Nsp2 and GP5 differences, in addition to the virulence difference between these two highly pathogenic PRRSV strains, have the potential to be used to establish a basis for further study of PRRSV virulence determinants and to provide data useful in the development of vaccines against this economically devastating disease.

Immunogenicity of tandem expression recombinant EG95s protein of Echinococcus g ranulosus / 中国人兽共患病学报

In order to analyze the immunogenicity of the recombinant EG95s protein ,the recombinant plasmids of pET-1EG95s ,pET-2EG95s and pET-3EG95s which containing respectively 1 ,2 ,and 3 copies EG95s were induced to express HIS-1EG95s ,HIS-2EG95s and HIS-3EG95s ,and then the proteins were purified and identified by western-blotting .The same im-mune process was used ,and 8 weeks-old BALB/c mice were immunized ,then its immunogenicity was analyzed by detecting an-tibody levels in mice by indirect ELISA method .Results showed that for recombinant EG95s proteins after transformation , HIS-1EG95s ,HIS-2EG95s ,and HIS-3EG95s also retained immunogenicity and could induce specific antibodies in mice .One week's late after the first immunization with HIS-1EG95s ,the antibody level of was significantly higher than HIS-2EG95s and HIS-3EG95s .But began from 2 weeks after immunization ,the antibody level of HIS-3EG95s was always higher than that of HIS-1EG95s group during the period of the immune .Both the final antibody titers after immunization of HIS-1EG95s and HIS-2EG95s groups was 1∶819 200 ,while HIS-3EG95s group was 1∶163 840 0 .HIS-1EG95s ,HIS-2EG95s and HIS-3EG95s all induced IFN-γin immune mice ,but the difference was not significant .The HIS-1EG95s showed lower response to Echinococ-cus granulosus positive serum than HIS-2EG95s and HIS-3EG95s .It’s indicated that the HIS-1EG95s and HIS-3EG95s also had good immunogenicity .HIS-3EG95s make recombinant protein immunic effects more lasting ,and benefit to generate more long-lasting protective immunity .This study provides the scientific basis for the immunization of echinococcosis (hydatidosis) .