杭州地区2009-2014年间人博卡病毒Ⅰ型的全基因组序列测定及遗传进化分析  

Genetic variation and molecular evolution of human bocavirus 1 strains isolated during 2009 to 2014 in Hangzhou, China

作　　者：周银燕[1] 李钧[1] 于新芬[1] 寇宇[1] 钱昕[1] 

机构地区：[1]杭州市疾病预防控制中心,310021

出　　处：《中华微生物学和免疫学杂志》2015年第6期401-406,共6页Chinese Journal of Microbiology and Immunology

基　　金：杭州市科技发展计划项目（20130733Q35）

摘　　要：目的调查杭州地区2009--2014年问人博卡病毒1型（humanbocavirus1，HBoV1）全基因组序列的遗传变异和分子进化特征。方法采集2009--2014年间浙江大学医学院附属儿童医院急性呼吸道感染患儿咽拭子标本，采用实时荧光PCR检测HBoV1，最终挑选15株病毒载量高的阳性样本进行全基因组扩增和测序。测序结果上传至GenBank，利用生物信息学软件分析序列。结果15株HBoV1病毒全基因组序列共检测到48个核苷酸突变，最终导致11个氨基酸变化，其中5个位点处于磷脂酶（PLA2）活性区。基于全基因组编码序列的进化分析表明HBoV1可以分为3个分支，本研究的15株病毒全部属于分支1，与瑞典代表株ST2属于同一簇。另外，进化树构建结果表明VP1／VP2基因可以替代全基因编码序列来构建HBoV1的进化树。HBoV1全基因组序列的进化速率为每年3．03×10-4（95％HPD，2．14×10-4～3．92×10-4）突变点／位点，对于单个基因，NS1的进化速率最慢，而NP1的进化速率最快。HBoV1四个基因的选择压力ω值部小于1，表明所有基因都处于纯化选择下，其中VP2的纯化选择压力最强，而NP1的纯化选择压力最弱。结论杭州地区2009—2014年间流行的HBoV1均属于ST2基因型，PLA2活性区变异率相对较高。全基因组序列虽然保守，但进化速率很快，其中NP1基因进化速率最快。4个基因均处于纯化选择压力下，其中VP2基因的纯化选择压力最强。Objective To investigate the genetic variation and molecular evolution of human bo- cavirus I （HBoV1） strains isolated during 2009 to 2014 in Hangzhou, China. Methods Throat swab sam- pies were collected from children with acute respiratory tract infections in the Children＇s Hospital Affiliated to the Zhejiang University School of Medicine from 2009 to 2014. Real-time PCR was performed for the detec- tion of HBoV1 strains. Fifteen HBoV1 strains with high virus load were screened out for the amplification and sequencing of complete geuomes. The complete genomes were submitted to GenBank for further analysis with bioinformatics software. Results A total of 48 nucleotide mutations were detected in the complete genomes of 15 HBoV1 strains, resulting in 11 amino acid mutations with 5 of them located in the active region of phospholipase A2 （PLA2）. The 15 HBoV1 isolates along with 16 HBoV1 strains in GenBank were classified into three clusters as indicated by the phylogenetic analysis based on their complete coding sequences. All of the 15 strains were belonged to cluster I , the representative strain of which was the Sweden prototype strain ST2. The phylogenetic trees constructed using genes encoding the capsid proteins VP1 and VP2 were highly similar to those based on the complete coding sequences. The estimated mean evolutionary rate of HBoV1 with regard to the complete coding sequence was 3.03×10-4（95% HPD, 2.14×10 4～3.92×10-4） substitu- tions per site per year. With regard to each gene, the NS1 gene was considered to the most conserved gene while the NP1 gene showed the highest substitution rate. The dN/dS ratios （to） of the four genes were all less than 1, indicating that all of them were under negative selection. Moreover, the VP2 gene was under the strongest negative selection, while the NP1 gene was under the weakest negative selection. Conclusion All of the HBoVI isolates circulating in Hangzhou province during 2009 to 2014 were belonged to ST2 genotype with a relatively high mutation i

关 键 词：人博卡病毒 呼吸道感染 全基因组 分子进化 

分 类 号：R373[医药卫生—病原生物学]