Sequence Feature Analysis Of VP1 Gene Of Enterovirus 71 From HFMD In Chongqing,2010-2015

Objectve: To study the characteristics of enterovirus 71 VP1 gene in children with hand foot mouth disease in recent 6 years in Chongqing area,and give basis to related research about VP1 gene of Enterovirus 71.Methods: Detect the pathogen type from stool samples collected from HFMD patients in Chongqing from 2010 to 2015.These complete VP1 genes were amplified and sequenced in our laboratory with enterovirus 71 specific primers by n RT-PCR.By random sampling,116 isolated strains are chosen to analyze gene homology,construct pjylogenetic tree.Vaccine Strain FY7VP5 being used as a control,compare the VP1 amino acid variation in Chongqing.Results:From 2011 to 2015,the virus isolates stains in Chongqing were all C4 a subtypes,which were highly homologous to the C4 a subtypes downloaded on Genebank.And there were two large epidemic branches at the same time,one of the pandemic branches had 4 small epidemic branches.In the construct pjylogenetic tree,temporal clusters can be found in Chongqing area,and there are differences in EV71 epidemic chain everyyear.2.Vaccine Strains including FY7VP5,H07,FY-23K-B,have high homology with all the virus isolated strains in Chongqing from 2010 to2015.3.In this study,we demonstrated amino acid variation at 15 positions and that 30 virus isolated strains are involved in.Conclusion: Molecular epidemiology shows:Enterovirus 71 isolated strains in Chongqing from 2010 to 2015 are all subtype of C4 a.There are different transmission chains in EV71 in Chongqing area,with time clustering.The nucleotide sequence of EV71 VP1 gene has changed over time.Enterovirus 71 vaccine(FY7VP5,H07,FY-23K-B)in Chinese market can cover all the virus isolated strains in Chongqing from 2010 to2015.Vaccine Strain FY7VP5 being used as a control,we find many amino acid variation positions,and large number of virus isolated strains involved in.A conclusion can be drawn that Enterovirus 7 has high varialbility.