重庆地区博尔纳病病毒种系发生分析

Phylogenetic analysis of Borna disease virus in Chongqing region

目的了解重庆地区博尔纳病病毒(Borna disease virus,BDV)基因特征及其种系发生。方法采用荧光定量巢式实时逆转录聚合酶链反应(fluorescence quantitative nested RT-PCR,FQ-nRT-PCR)检测健康牛、山羊、猪各50例以及病毒性脑炎(viral encephalitis,VE)患者20例外周血单核细胞(peripheral blood mononuclear cells,PBMCs)BDV p24片段,检出阳性序列和前期检出的5例重庆地区山羊和神经精神患者阳性BDV p24基因序列,与GenBank中5个国家7个动物种属33例BDV p24基因序列进行比对,分析其核苷酸和氨基酸序列同源性,重建基因系统发生树。结果10例BDV p24核苷酸序列一部分(1例VE患者)形成重庆独立支系,另一部分(7例动物和2例VE患者)汇聚至德国-瑞士-奥地利-日本-重庆混合支系。与BDV标准病毒株Strain V、H1766及He/80比对,9例核苷酸和氨基酸序列同源相似性分别为94%～100%和82%～100%,1例为95%～98%和89%～93%。结论重庆地区动物和人宿主可能存在地源性BDV独立株和源于外来疫病病原传入的流行株。

Objective To investigate the genetic characteristics and phylogeny of Borna disease virus （BDV） in Chongqing, China. Methods BDV p24 segment was detected by fluorescence quantitative nested RT-PCR （FQ-nRT-PCR） from peripheral blood mononuclear cells （PBMCs） of 50 healthy cattle, 50 healthy goats, 50 healthy pigs and 20 patients with viral encephalitis （VE）. Phylogenetic analysis of BDV p24 positive samples were performed by alignment with 5 positive gene sequences of healthy goats and patients with neuro- psychiatry diseases in preliminary studies in Chongqing and 33 sequences of 7 kinds of animal species in 5 countries from GenBank. The sequence homologous similarity of the nucleotide and the amino acid sequences was analyzed and gene phylogenetic tree was reconstructed. Results Among the 10 nucleotide sequences from Chongqing （including 3 strains from cattle, 2 from goat, 2 from pig and 3 from VE patients）, the sequence of 1 VE patient and those of our preliminary studies formed a Chongqing independent branch, and the other 9 sequences clustered within Germany-Switzerland-Austria-Japan-Chongqing mixed branch. Aligned with standard BDV strain V, H1766 and He/80, the homologous similarity in 9 sequences was 94% to 100% in nucleotide and 82% to 100% in amino acid, and the 1 sequence had a similarity of 95% to 98% in nucleotide and 89% to 93% in amino acid. Conclusion There may exist a Chongqing independent BDV strain from geographical origin, and the epidemic strain due to spread of foreign pathogen.