Isolation and identification of swine NDV JL01 strain and phylogenetic analysis of F gene / 病毒学报

An outbreak of fever and dyspnea with high incidence rate and case fatality rate occurred among pigs in a pigfarm in Jilin province, China, in 2000. The paramyxovirus-like particles could be observed in lungs, spleens and kidneys of the dead pigs under the transmission electron microscope. A Newcastle disease virus (NDV) isolate designated as JL01 was determined as the causal agent for the disease outbreak. The purified virus was reinoculated into pigs, and then the pigs infected with the virus showed similar symptoms, and the HI antibody of NDV could be detected from the reinoculated pigs. The MDT, ICPI and EID50 of the JL01 isolate was 55.2h, 1.60 and 10(-7.5)/0.1 mL respectively. The F gene of JL01 was cloned and sequenced, and the results showed that the identities of F gene shared by JL01 and avirulent NDV reference strains were from 91.5% to 98.5%, and could be ascribed to NDV genotype I. Thus, the swine NDV JL01 strain should be an avirulent strain with gene variation, but the virulence of JL01 was just the same as velogenic strains.

Expression of AIV subtype H5HA, H7HA and H9HA hemagglutinin gene in Pichia pastoris / 生物工程学报

The expression of the hemagglutinins of Avian influenza virus H5 H7and H9 subtypes was studied in this article by Pichia pastoris, one of the eukaryotis expression systems. Three reconstructed expression plasmids and engineering strains, named pPIC9K-H5HA, pPIC9K-H7HA, pPIC9K-H9HA and GS115/pPIC9K-H5HA, GS115/pPIC9K-H7HA, GS115/pPIC9K-H9HA repectively, were obtained. The reconstructed yeast engineering strains were identified by MD and MM plate selecting and PCR. The induced interests proteins were examined by SDS-PAGE and Western-bloting,the results showed that the interest genes were expressed exactly. And this will be helpful in the future study of antigen detection and antibody detection kit, as well in the subunit vaccines developing.