1.Predominant serotypes and VP1 gene analysis of Echovirus from viral encephalitis children in Quzhou area of Zhejiang province
Xiaofeng QIU ; Guoping CAO ; Jincao PAN ; Guozhong ZHANG ; Jun LI ; Bingdong ZHAN ; Shuchang CHEN ; Huakun LYU
Chinese Journal of Experimental and Clinical Virology 2020;34(2):169-174
Objective:To investigate the predominant serotypes and diversification of Echovirus (ECHOV) from viral encephalitis children in Quzhou area of Zhejiang province and the molecular characteristics of the ECHOV VP1 genes.Methods:Cerebrospinal fluid samples from 53 children with viral encephalitis were collected for viral isolation/culture. Fluorescent RT-PCR or PCR was used to detect human enteroviruses (HEV) including ECHOV, coxsackievirus(CoV) and new enterovirus (EV), and japanese encephalitis virus(JEV), mumps virus(MuV), west Nile virus(WNV) and chikungunya virus(CHLKV) or herpes simplex virus(HSV) and cytomegalovirus(CMV) in the cerebrospinal fluid samples. The complete VP1 gene sequence of HEV-B group in the HEV-positive cerebrospinal fluid samples was amplified by RT-PCR and sequenced, and then the typing of Echovirus isolates was performed. The VP1 genotypes of Echovirus isolates, gene recombination, inheritance and evolution characteristics were analyzed using multiple bioinformatic software.Results:Six viral strains were isolated by cell culture using rhabdomyosarcoma (RD) cells but not human epithelial-2 (Hep-2) cells. Eleven cerebrospinal fluid samples were positive for HEV by RT-PCR but the detection result of all the other viruses were negative. In the 11 HEV-positive samples, 6 samples were positive for ECHOV (4 for ECHO6, 1 for ECHO7 and 1 for ECHO30 serotype), which was coincident with the isolation result , but CoV and EV were undetectable. The 4 ECHO6 isolates belonged to ECHO6-C2 subgenotype but can be divided into two epidemic clones (ECHO6-41/46 and ECHO6-45/48). The ECHO7 and ECHO30 isolates belonged to ECHO7-C and ECHO30-C genotypes. The VP1 gene recombination between the ECHO6 and ECHO30 isolates were found during their evolutionary process.Conclusions:ECHOV is the major pathogen of viral encephalitis children in the area, and there is a possibility of local outbreak or epidemic. Because of the possibility of recombination of the VP1 gene of ECHO6 and ECHO30 virus, ECHO6 may become the dominant ECHOV serotype.