人冠状病毒HKU1 N和S蛋白基因序列及进化分析

Sequencing and phylogenetic analysis of the N and S genes of human coronavirus HKU1 in Fuzhou,China

目的了解人冠状病毒HCoV-HKU1在我国福州急性重症下呼吸道感染患儿中的感染情况以及病毒N基因和S基因的系统进化特征。方法通过RT-PCR法对2007年11月至2015年1月因呼吸道感染住进医院儿科重症监护病房的266例小儿鼻咽抽取物标本进行4种人冠状病毒的检测和人冠状病毒HCoV-HKU1的确认检测,测序并BLAST比对分析8份人冠状病毒阳性产物。结果在266例标本中检出2例HCoV-HKU1感染阳性病例,检出率为0.75%(2/266)。这两例患儿一例诊断为支气管炎、一例诊断为急性重症肺炎。通过检测都发现混合感染了人副流感病毒3型(HPIV-3)。对这两株病毒FZ90和FZ96的N和S蛋白基因进行序列测定、拼接和系统进化分析;结果表明这2株HCoV-HKU1都属于HKU1基因型A。结论人冠状病毒HCoV-HKU1可能是儿童下呼吸道感染中较为重要的一种病原,混合感染导致儿童病情加重。

The aim of this study was to characterize the N and Sprotein encoding genes of human coronaviruses（HCoVHKU1）in children with respiratory tract infection in Fuzhou,Fujian,China.Nasopharyngeal aspirates were collected from children with respiratory tract disease from Nov 2007 to Jan 2015.A total of 266 clinical samples were tested for HCoVs using reverse-transcription polymerase chain reaction（RT-PCR）.The positive products were sequenced and compared with those in GenBank by Blast.The positive samples were then tested for HCoV-HKU1 using RT-PCR method.HCoV-HKU1 were detected in 2 patients（0.75%）out of the 266 children.One of children who were positive for HCoV-HKU1 was diagnosed as bronchitis,and the other was serious acute pneumonia.Co-infections with human parainfluenza virus type 3（HPIV-3）were found in the two HCoV-HKU1 positive samples.We compared the N and S gene sequence of the 2 HCoV-HKU1 isolates in Fuzhou,China to other HCoV-HKU1 isolates documented in the GenBank database by using MEGA software version 6.06 and the neighbor-joining method.Phylogenetic analyses revealed that the 2 strains of HCoV-HKU1 were genotype A.HCoV-HKU1 infections were associated with upper and lower respiratory illness in children.