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Objective To analyze and trace the infection source the envelope(E) gene of the new emerged type 3 dengue virus in Guangzhou in 2009. Methods Sera were collected from patients infected with local dengue fever. Dengue virus was cultured and isolated by C6/36 cells. The whole length E gene was amplified from the positive specimen by RT-PCR, thereby sequenced and phylogenetic tree drawn by neighbor-joining method. Both data on epidemiologic and molecular studies were processed and analysed. Results 7 strains of type 3 dengue virus were isolated from samples of the 19 patients. E gene of these strains was amplified. The complete E genes of 7 strains belonged to 1479 nucleotides in length, encoding a polyprotein of 493 amino acids. Data from the phylogenetic analysis showed that 09/GZ/1081, 09/GZ/1483 and 09/GZ/10806 strains fell within the Southeast Asia/South Pacific group. 09/GZ/10616, 09/GZ/11144, 09/GZ/11194 while 09/GZ/13105 strains fell within the India group. Conclusion The type 3 dengue virus identified in Guangzhou area in 2009 was imported and could be devided into two genotypes.
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Objective To analysis the E protein epitopes of dengue virus type 1-4, Japanese encephalitis virus and yellow fever virus and to distinguish the shared or specific epitopes among them. Methods Bioinformatic software DNAStar was used to analyze the hydrophilicity, flexibility, surface probability and antigenicity of dengue virus type 1-4, Japanese encephalitis virus and yellow fever virus E prtein amino acid sequences. The influence of secondary structure was also considered. Based on the bio-informatic analysis of E protein epitopes, 6 specific epitopes were amplified and inserted into prokaryotic expression vector pMAL-c2x. The vectors was then transferred into E.coli BL21 (DE3) and Rosetta (DE3). Isopropyl-β-D-thiogalactoside (IPTG) was used to induce the expression of gene segments and SDS-PAGE were used identify the expression proteins. The antigenieity was tested, using Western blot. Results 15 shared epitopes and 47 specific epitopes were forecasted by bioinformatic analysis, and 6 specific epitopes from dengue virus type 1-4, Japanese encephalitis virus and yellow fever virus E protein were expressed in E.coli successfully. Two specific antigenic determinant from dengue virus type 1 and dengue virus type 2 were confirmed using Western blot, while the others epitopes shown no antigenic reaction property. Conclusion Two specific antigenic determinant were confirmed, under Western blot.
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<p><b>OBJECTIVE</b>To study the relation of the detection rates of the novel influenza virus A/H1N1 RNA in clinically confirmed patients in the 2009 pandemic with the age distribution of the patients and the disease course.</p><p><b>METHODS</b>A total of 151 clinical patients with H1N1 infection were enrolled in this study, from whom 833 dynamic throat swab samples were obtained for detecting the H1N1 RNA using real-time PCR. A statistical analysis of the age distribution was performed among the patients with different disease courses. Chi-square for trend test was used to study the correlation between the detection rates of H1N1 RNA and the time of disease onset.</p><p><b>RESULTS</b>The majority of patients were young with their ages ranging from 10 to 20 years (57.26%) and 20 to 30 years (22.18%). Chi-square for trend test revealed that the positivity rates of the throat swabs in the patients decreased with the prolongation of the disease course (chi(2)=9.784, P=0.002).</p><p><b>CONCLUSION</b>Most of the H1N1 patients are young within the age range of 10-30 years, and the longest disease course can exceed 10 days. The positivity rates of throat swabs from the H1N1 patients decreases with the prolongation of the disease course.</p>
Subject(s)
Adolescent , Adult , Child , Female , Humans , Male , Young Adult , Age Factors , China , Epidemiology , Influenza A Virus, H1N1 Subtype , Genetics , Influenza, Human , Epidemiology , Virology , Pharynx , Virology , RNA, Viral , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
A new automatic selection approach of microorganism specific fragment combination is presented in this paper. Genetic algorithm is used to search optimal solution on the basis of classification ability of SNP combination, which is evaluated by the rough set theory. Other related experimental parameters are also been incorporated. Experimental results show that the method can find the best SNP combination pattern efficiently and accurately, which implies that it is a reliable approach to the genechip probe design.