白纹伊蚊体内沃尔巴克氏体感染及基因分型调查

Wolbachia infection and genotyping in Aedes albopictus

【目的】了解白纹伊蚊体内沃尔巴克氏体(Wolbachia)的感染及基因分型情况。【方法】2020—2021年采集居民区和野外区的白纹伊蚊成蚊和幼虫标本,采用聚合酶链反应(PCR)扩增沃尔巴克氏体表面蛋白(wsp)基因并进行wAlb A和wAlb B分型扩增,测序并进行系统进化分析;不同地区生境、雌雄成蚊及成蚊幼虫之间的检出率差异采用χ^(2)检验。【结果】白纹伊蚊成蚊和幼虫的沃尔巴克氏体检出率分别为43.5%(77/177)和70.4%(190/270),差异有统计学意义(χ^(2)=32.086,P<0.001),均以共同检出wAlb A和wAlb B为主;白纹伊蚊雌蚊和雄蚊的沃尔巴克氏体检出率分别为50.7%(76/150)和3.7%(1/27),差异有统计学意义(χ^(2)=20.533,P<0.001);松江野外区、居民区及虹口居民区的白纹伊蚊成蚊沃尔巴克氏体检出率分别为91.7%(55/60)、18.8%(22/117)和41.7%(30/72),差异有统计学意义(χ^(2)=54.322,P<0.001)。基因分型和系统进化分析显示,白纹伊蚊成蚊和幼虫感染沃尔巴克氏体主要为A群wAlb A型和B群wAlb B型;另外存在个别序列单独形成进化枝,且与其他序列的遗传距离较大。【结论】松江区白纹伊蚊体内沃尔巴克氏体的感染情况较普遍,基因型主要有wAlb A型和wAlb B型,可能还存在其他亚型,值得进一步探究。

[Objective]To investigate the infection and genotypes of Wolbachia in Aedes albopictus.[Methods]Adult and larval samples of Aedes albopictus were collected from different residential and wild areas from 2020 to 2021,Wolbachia surface protein(wsp)gene was amplified and genotyped for wAlbA and wAlbB by PCR,and sequenced for phylogenetic analysis.The difference of detection rate among different habitats,male and female adult mosquitoes,adult and larvae was compared byχ^(2) analysis.[Results]The detection rate of Wolbachia in adult and larvae of Aedes albopictus were 43.5%(77/177)and 70.4%(190/270),respectively,with a statistically significant difference(χ^(2)=32.086,P<0.001),and wAlbA and wAlbB were mainly detected together.The detection rate of Wolbachia in female and male Aedes albopictus were 50.7%(76/150)and 3.7%(1/27),respectively,with a statistically significant difference(χ^(2)=20.533,P<0.001).The detection rate of adult Aedes albopictus in Songjiang wild area,residential area and Hongkou residential area were 91.7%(55/60),18.8%(22/117)and 41.7%(30/72),respectively,with a statistically significant difference(χ^(2)=54.322,P<0.001).Genotyping and phylogenetic analysis showed that adult and larvae of Aedes albopictus infected with Wolbachia were mainly wAlb A and wAlb B.In addition,some sequences formed clades independently,and the genetic distance from other sequences was relatively large.[Conclusion]Infection of Wolbachia in Aedes albopictus is relatively common in Songjiang District.The main genotypes are wAlb A and wAlb B and there may be other subtypes,which are worthy of further exploration and research.