Isolation and identification of Coxsackievirus A16 strains in Kunming,Yunnan Province in 2019 and analysis of genetic characteristics of VP1 gene / 中国生物制品学杂志

ABSTRACT

@#Objective To analyze the genetic characteristics of the entire VP1 gene of Coxsackievirus A16(CVA16) strains isolated from the feces of patients with hand,foot and mouth disease(HFMD) in Yunnan Province in 2019.Methods The virus was isolated from human embryonic lung diploid fibroblast(KMB-17) cells and African green monkey kidney(Vero)cells,and the primers for the complete VP1 gene sequence of CVA16 were designed.The target fragment was amplified by RT-PCR and sequenced;the complete VP1 sequence was analyzed by softwares such as MEGA 7.0 and Geneious 9.0.2.Results A total of 26 CVA16 strains were isolated,including eight KMB-17 isolates and 18 Vero isolates.Twenty CVA16isolates were randomly selected for analysis,and three isolates were found to have Bla and 17 B1b genotypes;the nucleotide and amino acid homology of 17 CVA16 B1b isolates were 93.8%—100% and 98.3%—100%,and the nucleotide and amino acid homology with other domestic isolates was 91.1 %—99.2% and 97.3%—99.0%,respectively;the nucleotide and amino acid homology of the three Bla isolates was 98.0%—98.1% and 99.3%,and those with other domestic Bla isolates was 88.7%—98.1% and 98.3%—99.7%,respectively;17 B1b isolates and other three Bla isolates showed the nucleotide and amino acid homology of 87.4%—88.4% and 97.3%—98.7%.Conclusion The CVA16 prevalent in Kunming in 2019 belonged to Bla and B1b genotypes,with B1b as the main strain,and all of them were prevalent strains in the mainland of China.