南宁市37例登革病毒1型E基因系统进化分析

目的 对南宁市37例登革病毒1型（DENV1）流行株E基因进行序列测定，分析其分子生物学特征，探讨其可能来源。方法 选取2014年12份、2019年25份，共37份经确证为DENV1感染者阳性血浆样本，RT PCR扩增E基因片段，测序后进行同源性比较、系统进化分析。结果 测序后共获得37条长度为1437bp的E基因核苷酸序列，与各参考株E基因序列构建系统进化树后共形成Ⅰ、Ⅱ、Ⅲ，3个较大的进化簇，进化簇Ⅰ包括10条2019年DENV1 E基因序列，与参考序列Singapore 2017遗传距离最近，序列相似度99.4%~99.5%；进化簇Ⅱ包括8条2019年DENV1 E基因序列，与参考序列GuangZhou 2018遗传距离最近，序列相似度99.3%~99.5%；进化簇Ⅲ包括7条2019年DENV1 E基因序列和8条2014年DENV1 E基因序列，与参考序列Vietnam 2016遗传距离最近，序列相似度98.4%~98.8%。结论 2019年南宁市输入性DENV1流行株最有可能来源于广州和越南，推断南宁市2019年出现的DENV1本地流行由2014年以来本地进化毒株和新输入毒株共同引起。

Phylogenetic analysis on the E gene of 37 DENV I virus in Nanning

To find out the phylogenetic evolution tendency and the biological origin of 37 dengue virus type 1(DENV1) epidemic in Nanning City by E gene sequencing. Methods A total of 37 dengue virus type 1 positive serum samples of dengue patients from 2014 and 2019 in Nanning City were collected, E gene fragment of dengue virus type 1 amplified by RT-PCR then sequencing, and the phylogenetic tree of the DENV1 E gene together with reference sequences were constructed, similarity comparison and phylogenetic analysis was carried out. Results Succeeding in amplify 37 E gene nucleic acid fragments of 1 437 bp length, phylogenetic tree demonstrate three principal cluster namedⅠ, Ⅱ, Ⅲ were confirmed.ClusterⅠincluded 10 sequences of 2019 DENV1 E gene sequence and had the nearest genetic distance from reference sequence Singapore 2017 with a sequence similarity rate between 99.4%-99.5%. ClusterⅡincluded 8 sequences of 2019 DENV1 E gene sequence and had the nearest genetic distance from reference sequence GuangZhou 2018 with a sequence similarity rate between 99.3%-99.5%. Cluster Ⅲ 7 sequences of 2019 and 8 sequences of 2014 DENV1 E gene sequence had the nearest genetic distance from reference sequence Vietnam 2016 with a sequence similarity rate between 98.4%-98.8%. Conclusion The dengue virus type 1 pandemic in Nanning 2019 are originated from neighboring district such as Guangzhou and Vietnam. DENV1 has been emerged local tansmission common originated from Local DENV-1 evolution strains and 2019 imported DENV1 strains.