To construct the bi-valent genetic engineering vaccine against pseudorabies virus（PRV）and porcine reproductive and respiratory syndrome virus（PRRSV）,the modified PRRSV ORF5 gene（ORF5M） and the VP22 gene of bovine herpesvirus 1（BHV-1）,which encodes VP22 protein and has been demonstrated to exhibit the unusual protein transduction property,were inserted into a PRV universal transfer vector pIECMV by turns.A recombinant virus transfer vector pIECMV-VP22ORF5M possessing VP22-ORF5M fusion gene was generated.The recombinant virus transfer vector pIECMV-VP22ORF5M co-transfected the IBRS-2 cells with PRV TK-/gE-/LacZ+ genomic DNA digested by EcoRⅠusing liposome method.Based on homologous recombination,the recombinant virus was generated and then purified by the plaque assay and PCR amplification.After three rounds of plaque purification,the recombinant virus was further confirmed by PCR,Southern blot and Western blot.A recombinant PRV（rPRV）TK-/gE-/VP22GP5+ expressing VP22-GP5 fusion protein was constructed.The results of TCID50 tests showed that the insertion of the foreign genes had no influence on the propagation of rPRV in IBRS-2 or PK-15 cells.The construction of rPRV TK-/gE-/VP22GP5+ provides a basis for further study of bi-valent genetic engineering vaccines against PRRSV and PRV,and that this strategy may also be useful to develop more efficient genetic engineering vaccines against other pathogens.
猪圆环病毒2型(porcine circovirus type 2,PCV2)主要引起猪的多系统功能障碍性疾病,同时,还可侵害猪的免疫系统,造成猪免疫抑制,容易继发细菌及其他病毒感染,大大增加猪群的死亡率。为了解PCV2在浙江金华猪群中的分布与流行状况以及PCV2变异规律,对从浙江省金华猪场收集的3 433份血清进行PCR检测,结果显示,2012-2018年PCV2阳性率分别为10.16%,11.95%,8.50%,9.94%,6.19%,5.94%,8.28%,母猪阳性率最高为13.49%。本研究发现在2012年浙江金华地区PCV2优势毒株已经由PCV2b变为PCV2d,且全部为PCV2d-2。将得到的ORF2序列同已知的疫苗序列对比后,发现SH株与浙江金华目前PCV2主流毒株序列一致性最高,但抗原位点比较仍有5处差异,这可能会对疫苗效果产生影响,需要进一步验证。另外只有PCV2d在免疫显性诱饵表位上发生了突变,这可能是PCV2d成为主流的原因。
