| Objective: To find out the EV71epidemic in2009to2011in Dalian; EV71strainsisolated part of the gene fragment of the nucleotide and amino acid sequencedetermination, phylogenetic trees and homology analysis, to determine theirgenotype;compared with strain virulence gene sequence analysis, to explore therelationship between strain virulence gene sequences, to provide a scientific method forprevention, treatment and control of EV71in the futureMethods: The case of hospital outpatient visits in Dalian City, hand, foot andmouthdisease sentinel surveillance sites and hand-foot-mouth-like cases from sentinelsurveillance hospitals, throatswab and stool specimens using fluorescent RT-PCRmethod detected as EV71positive samples were inoculated into RD cellsseparation ofEV71virus after subculture to extract viral RNA by RT-PCRmethod of VP1, VP4,5’UTR gene fragments were amplified, PCR products weresequenced using theDNAStar software and EV71genesubtype representative strains of the sequenceanalysis of the relationship between the nucleotide andamino acid sequence homology,as well as different clinical symptoms of strainand the nucleotide and amino acidsequenceResults:1.In2009~2011period533samples were detected, of which333copies ofEV71is positive, the positive rate is62.48%. In533cases,317cases of male and216cases offemale, male to female ratio1.47:1. Positive rate of Male patients-EV71is61.51%,positive rate of female patients is63.89%.0-5years kids for hand, foot and mouthdisease is high incidence, mainly are kindergarten kids.2.The VP1region sequence analysis showed that: select9of RD cells wereisolated and cultured strains of EV71VP1sequence was amplified and sequenced, theresults with DNAStar software analysis,9EV71strains to C4a subtypes, thenucleotidehomology between88.7%to99.9%;96.7%to100%homologybetweenthe amino acids. The BRCR-CA-70nucleotide homology of79.4%to81.5%;and B nucleotide homology:81.8%to84.7%; subtype C nucleotide homology of85.2%99.2%, while90.0%to99.2%, homology with C4and C4a of the highesthomologyof93.7%to99.2%,90.0%and94.1%homology with C4b of. Severe sourceofstrain in the first227nucleotides of the Tâ†'C base substitutions, and mild source ofthe strains were not changed. Found no consistent change in the amino acid sequence3.The VP4region sequence analysis showed that the highly consistent: VP4aminoacid sequences of nine strains, the Kâ†'R change only occurred in52dalian1-09strains,62amino acids dalian4-10strains in the Tâ†'Schange the rest of theamino acidsequences of strains. Did not find a severe source of strain and mildsource of strain inthe corresponding fixed amino acid or nucleotide sequencevariation4.5’UTR of District Sequence analysis showed that: the sample of nine strains208nucleotides, severe sources base substitution (Gâ†'A); in the sample of254nucleotides, severe sources occura base substitution (aâ†'G). The amino acidsequence found no consistent changeConclusion:1. EV71is major pathogens and the genotype is C4a subtype of hand, foot andmouth disease in Dalian from2009to2011, which is consistent with the Chinesemainland in most parts of epidemic strains.2. consistent genotyping based on VP4genotyping with the VP1are C4asubtype,and the VP4sequence highly conserved.3. In the analysis of the strain’s virulence, severe source of strain, the first227nucleotides of the VP1, a Tâ†'C base substitutions, mild sources of strain werenotchanged. The VP4nucleotide and amino acid sequences were not foundtocorrespond to changes in clinical symptoms, found in the5’UTR sequence of208nucleotide base substitution (Gâ†'A), this result remains to be in the conductoffuture research. |
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