Molecular Epidemiological Investigation And Serotyping Study Of Enterovirus Were Associated With Hand,foot,and Mouth Disease From Shandong

Background and ObjectiveHFMD is an acute infectious disease with typical clinical manifestations:maculopapular of vesicular rash on the palms and soles and vesicles or ulcers in the mouth.And children with serious complications,including myocarditis,pulmonary edema,aseptic meningitis,encephalitis,were considered as severe HFMD,which caused by enterovirus,especially under 5 years.HFMD was prevalent in many countries and regions repeatedly.HFMD has affected almost all provinces and regions in China since the outbreak in Fuyang,Anhui and the number of infections and deaths is rising year to year since then.Coxsackieviruses A10(CVA10)and A6(CVA6)have been associated with increasingly occurred sporadic hand-foot-mouth disease(HFMD)cases and outbreak events globally in recent years.And different genotypes were prevalent alternately every two years.There are different genotypes of enterovirus in almost every year.In recent years,other types,especially CVA10 and CVA6,began to co-circulate with increasingly frequencies,turning into equally common causes of HFMD as CVA16 and EV71 in certain regions.So,accompanied by the rises of the proportion,the status of other enteroviruses is equally important to the EV71 and CVA16 of HFMD.As the heavily inflicted regions with HFMD,there are different epidemic strains in different regions of Shandong province.And information on the pathogenic role of other enteroviruses is also still lacking.Therefore,our study,which represents a comprehensive molecular epidemiologic investigation and simple Genotyping-by-Sequencing is very important.By studying the prevalence and genetic characteristics of enteroviruses and analysing sequence features and evolutionary laws,we explore their characteristics of origin,evolution rate,gene recombination and propagation and the relationship of virus variation and prevalence,which help to fully grasp their geographic distribution and epidemiological profiles,classification and evolution of circulating strains about HFMD in Shandong in the past two years.And we could deeply understand the pathogenesis of HFMD,which provides consideration and guidance for physicians.MethodsWe collected virus supernatants and fecal samples from Shandong center for disease control and prevention,which was derived from Taian,Dezhou,Dongying and Weihai,at least 40 strains from every city.We collected the supernatants when the cells had cytopathic effect(CPE).According to geographical and temporal specific distributions of the strains,30 ul RNAs were extracted from representative strains.And HEV genomes were sequenced.Similarities between strains were calculated by using Bio Edit.Phylogenetic trees were constructed by using Meg5.Further studies should be performed by the genetic similarity and phylogenetic tree.ResultsThere are total 25 strains genome sequences of the other enteroviruses,which were isolated from virus supernatants from Shandong center for disease control and prevention,including 11 strains of CVA10?5 strains of CVA6?1 strains of CVA2?3 strains of CVA4?4 strains of CVB4 and 1 strains of CVB5.By stool samples,187 strains were isolated in nine cities from Shandong province and 26 strains genome sequences had been measured,which included CVA2,CVA4,CVA6,CVA12 and CVA14 and other genotypes.Similarities between strains were calculated by using Bio Edit.Phylogenetic trees of CVA10 and CVA6 were constructed by using RAXML and Meg5,respectively.We found that the CVA10 and CVA6 strains had the characteristics of inter-regional exchange and genetic diversity.And two Zhejiang strains of CVA10 exist recombination events.Conclusion1.CVA10 and CVA6 strains have shown regional exchange characteristics;2.CVA10 and CVA6 strains have characteristics of genetic diversity;3.Two Zhejiang strains of CVA10 exist recombination events.