RESUMEN
@#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.
RESUMEN
Coxsackievirns A16(CVA16),together with enterovirus type 71(EV71),is responsible for most cases of hand,foot and mouth disease(HFMD) worldwide.Recent findings suggest that the recombination between CVA16 and EV71,and the co-circulation of these two viruses may have contributed to the increase of HFMD cases in China over the past few years.It is therefore important to further understand the virology,epidemlology,virus-host interactions and host pathogeuesis of CVA16.In this study,we describe the viral kinetics of CVAI6 in human rhabdomyosarcoma(RD) cells by analyzing the cytopathic effect(CPE),viral RNA replication,viral protein expression,viral RNA package and viral particle secretion in RD cells.We show that CVA16 appears to first attach,uncoat and enter into the host cell after adsorption for 1 h.Later on,CVA16 undergoes rapid replication from 3 to 6 h at MOI 1 and until 9 h at MOI 0.1.At MOI 0.1,CVA16 initiates a secondary infection as the virions were secreted before 9 h p.i.CPE was observed after 12 h p.i.,and viral antigen was first detected at 6 h p.i.at MOI 1 and at 9 h p.i.at MOI 0.1.Thus,our study provides important information for further investigation of CVA16 in order to better understand and ultimately control infections with this virus.