广州市2009年新出现登革3型病毒的分子流行病学分析

目的 对广州市2009年新出现的3型登革病毒(DEN)株的E基因进行RT-PCR扩增和序列测定,探讨其来源及基因型.方法 收集广州市2009年登革热患者急性期血清,用C6/36细胞培养分离DEN,RT-PCR扩增病毒全长E基因,测序并绘制系统进化树,结合流行病学资料进行分子流行病学分析.结果 2009年采集的19份患者血清标本中,分离到7株3型DEN株,RT-PCR扩增后测序获得E基因序列,7株DEN3病毒E基因均由1479个碱基组成,编码493个氨基酸,基因序列未见插入或缺失,分析发现7株病毒来自两个不同的亚型:09/GZ/1081、09/GZ/1483和09/GZ/10806属于东南亚/南太平洋型,09/GZ/10616、09/GZ/11144、09/GZ/11194和09/GZ/13105属于印度次大陆型,各亚型群内毒株序列同源性较高.结论 广州市2009年DEN3为输入性,分属两个基因型.

Molecular epidemiologic analysis on new emerged type 3 dengue virus in Guangzhou in 2009

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.