Investigation of avian diseases eradication in parent breeding flocks in China in 2015 / 中国兽医学报

In order to understand the management measures,technique abilities and difficulties in controlling and eradicating avian diseases in parent breeding flocks,the current situation of avian disease eradication in breeding flocks was investigated by China Animal Disease Control Centre in 19 provinces in July 2015.Questionnaires investigation was conducted and the feedbacks were received from 214 parent breeding flocks.This study summarized and analyzed the information of farm management,breeding resources,avian disease surveillance and disease eradication in these flocks,which will provide the basic data to promote the avian diseases control and eradication in China.

Expression and identification of truncated Nsp7 protein of North American and Europe genotype porcine reproductive and respiratory syndrome virus / 生物工程学报

Porcine reproductive and respiratory syndrome virus (PRRSV) non-structural protein 7 (Nsp7) plays an important role in the induction of host humoral immune response and could serve as an ideal antigen for serological genotyping assay for PRRSV based on the significant difference in immunoreactivities of North American (NA) and European (EU) PRRSV Nsp7. In this study, Nsp7 of NA and EU PRRSVwas separately expressed and purified using prokaryotic expression system. The purified recombinant Nsp7 proteins reacted with serum antibodies against corresponding genotype PRRSV in Western blotting. However, nonspecific reaction of whole recombinant Nsp7 with antibodies against another genotype PRRSV was observed, indicating that whole NA PRRSV Nsp7 and EU PRRSV Nsp7 have similar antigenic epitopes and recombinant proteins could not be used for genotyping of antibodies against PRRSV. Based on the analysis of similar antigenic epitopes at the hydrophilic region of NA PRRSV Nsp7 and EU PRRSV Nsp7 by bioinformatics assessment, partial Nsp7 gene region deleted sequences encoding similar antigenic epitopes was constructed by fusion PCR. The recombinant truncated Nsp7 (NA-deltaNsp7 and EU-deltaNsp7, about 43 kDa) was expressed and the molecular weight was about 43 kDa. The results of Western blotting showed that NA-deltaNSP7 and EU-deltaNSP7 could be specifically recognized by positive serum to NA or EU PRRSV individually and nonspecific reaction was eliminated. This study provided a basis for further development of serological genotyping assay for North American and European genotype PRRSV infection.