Genetic characterization of Chikungunya virus from New Delhi reveal emergence of a new molecular signature in Indian isolates.
Genetic characterization of Chikungunya virus from New Delhi reveal emergence of a new molecular signature in Indian isolates.
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DOI：
10.1186/1743-422x-9-100
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发表时间：
2012-05-25
期刊：
影响因子：
4.8
通讯作者：
Sunil S
中科院分区：
文献类型：
--
作者：
Shrinet J;Jain S;Sharma A;Singh SS;Mathur K;Rana V;Bhatnagar RK;Gupta B;Gaind R;Deb M;Sunil S
基孔肯雅热（CHIK）目前在印度南部和中部流行，并在印度北方与登革热合并感染。2010年，新德里在3月至12月爆发了CHIK。这是德里首次发生占优势的CHIK疫情，促使我们对德里病毒株进行表征。我们还调查了CHIK在印度传播的演变。对临床标本进行RT-PCR检测CHIK病毒RNA。对PCR扩增产物进行测序，并对所得序列进行遗传分析。基于结构蛋白E1和E2部分序列的系统发育分析显示，最近一次爆发的病毒具有ECSA谱系。两个新的突变，E1 K211 E和E2 V264 A在所有德里分离株。此外，来自印度八个州的CHIKV序列与德里序列沿着进行了分析，以绘制该国CHIKV的遗传多样性。国家内的平均进化分歧的估计表明，不同的国家和国家之间的序列之间的分歧。我们鉴定了CHIKV的不同基因型的不同分子特征，揭示了在新德里进化枝中出现的新特征。统计分析和构建病毒在国内的进化路径显示，一种特定毒株在全国范围内逐渐传播。这项研究已经确定了E1和E2基因中的独特突变，并揭示了在马哈拉施特拉邦传播的具有最大多样性的祖先CHIKV群体的存在。该研究进一步揭示了自1963年第一次报告以来以及随后在2005年再次出现以来，印度CHIK传播的趋势。
Chikungunya (CHIK) is currently endemic in South and Central India and exist as co-infections with dengue in Northern India. In 2010, New Delhi witnessed an outbreak of CHIK in the months October-December. This was the first incidence of a dominant CHIK outbreak in Delhi and prompted us to characterize the Delhi virus strains. We have also investigated the evolution of CHIK spread in India. Clinical samples were subjected to RT-PCR to detect CHIK viral RNA. The PCR amplified products were sequenced and the resulting sequences were genetically analyzed. Phylogenetic analysis based on partial sequences of the structural proteins E1 and E2 revealed that the viruses in the latest outbreak exhibited ECSA lineage. Two novel mutations, E1 K211E and E2 V264A were observed in all Delhi isolates. In addition, CHIKV sequences from eight states in India were analyzed along with Delhi sequences to map the genetic diversity of CHIKV within the country. Estimates of average evolutionary divergence within states showed varying divergence among the sequences both within the states and between the states. We identified distinct molecular signatures of the different genotypes of CHIKV revealing emergence of a new signature in the New Delhi clade. Statistical analyses and construction of evolutionary path of the virus within the country revealed gradual spread of one specific strain all over the country. This study has identified unique mutations in the E1 and E2 genes and has revealed the presence of ancestral CHIKV population with maximum diversity circulating in Maharashtra. The study has further revealed the trend of CHIK spread in India since its first report in 1963 and its subsequent reappearance in 2005.