Expression and activity determination of recombinant capsid protein VP2 gene of enterovirus type 71 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To clone and express the recombinant capsid protein VP2 of enterovirus type 71 (EV71) and to identify the immune activity of expressed protein in order to build a basis for the investigation work of vaccine and diagnostic antigen.</p><p><b>METHODS</b>VP2 gene of EV71 was amplified by PCR, and then was cut by restriction enzyme and inserted into expression vector pMAL-c2X. The positive recombinants were transferred into E.coli TB1, the genetically engineered bacteria including pMAL-c2X-VP2 plasmids were induced by isopropyl thiogalactoside ( IPTG) , and the expression products were analyzed by SDS-PAGE and western blotting method. EV71 IgM antibody detection method by ELISA was set up, and the sensitivity and specificity of this method was assessed; 60 neutralizing antibody positive serum samples from hand foot and mouth disease (HFMD) patients were determined, of which 52 samples were positive and 8 samples were negative; a total of 88 acute phase serum samples of HFMD patients diagnosed in clinical were also detected.</p><p><b>RESULTS</b>VP2 gene of 762 bp was obtained by PCR, the gene segment inserted into the recombinant vector was identified using restriction enzyme digestion. The recombinant vector could express a specific about 71 500 fusion protein in E.coli by SDS-PAGE. The purified recombinant protein of EV71-VP2 can react with the serum of HFMD patients to produce a specific band by western blotting. The sensitivity and specificity of ELISA was 87% and 83%, respectively. Of the 88 acute phase serum samples from children with HFMD, 48 samples (55%) were positive by the ELISA assay.</p><p><b>CONCLUSIONS</b>VP2 gene of EV71 has been cloned and a prokaryotic high expression system for VP2 gene was successfully constructed in the present study. The recombination EV71-VP2 has well antigenicity, which could be useful for developing diagnose reagent or vaccine of EV71.</p>

Study on the genetic characteristics and molecular epidemiology of Echovirus 11 strains isolated from patients with hand food and mouth disease in He-nan province, China / 中华微生物学和免疫学杂志

Objective To analyze the evolution and genetic characteristics of Echovirus 11 (Echo11) strains isolated from patients with hand food and mouth disease ( HFMD) in Henan province. Methods Enterovirus strains were isolated from stool samples of patients with HFMD from year 2010 to 2012.The sequences of VP1 region of all positive strains were amplified , sequenced and then analyzed by BLSAT to determine their genotypes .The entire VP1 coding regions of 10 Echo11 strains were amplified by RT-PCR, and the homology analysis was conducted among them and other Echo 11 strains published in Gen-Bank.A phylogenetic tree was constructed to evaluate the evolution of Henan isolates and the prevalence of different genotypes .Results From year 2010 to 2012 , 184 non-Enterovirus 71 ( EV71 ) strains and non-Coxsakievirus A16 (CA16) strains causing HFMD were isolated, 10 (5.43%) of with were Echo11 strains. There were 876 nucleotides ( nt) in the complete VP1 gene sequence , encoding 292 amino acids ( aa) .The 10 Echo11 strains shared 93.1%-100% homologies in nt sequences and 97.3%-100% in aa sequences. The homology analysis indicated that Henan strains and prototype strains were highly similar but different with the homology of 77.8%-78.8% in nt and 90.8%-91.8% in aa, respectively.Conclusion Echo11 was one of the pathogens causing HFMD in He-nan province and genotype A was the dominant genotype .

Ecological study on the relationship between meteorological factors and incidence of fever, thrombocytopenia and leukopenia syndrome (FTLS) / 中国人兽共患病学报

To explore the relationship between meteorological factors and incidences of fever, thrombocytopenia and leukopenia syndrome (FTLS), incidence data of FTLS in Xinyang City were collected and described. The relationship between FTLS and monthly meteorological factors such as average atmospheric pressure, average temperature, average relative humidity, average wind speed and precipitation was analyzed with simple correlation and multi-stepwise linear regression. The results showed that there was a significant negative correlation between incidence of FTLS and monthly average atmospheric pressure (P<0.01), and there were significant positive correlations between monthly average temperature, monthly average relative humidity, monthly precipitation and incidence of FTLS (P<0.05). The multi-stepwise regression showed that the regression equation was Y (monthly cases) =-12.70 + 0.28X2 (monthly average temperature), and the coefficient of determination was 0.76. The incidences of FTLS are correlated with temperature.