巢氏PCR判定西藏疟疾流行区传疟媒介

目的确定西藏墨脱县疟疾流行区的疟疾传播媒介。方法根据2005、2006和2007年疟疾发病情况,在墨脱县选择了3个疟疾发病较高的自然村,采用人诱、牛诱、灯诱及清晨人房全捕等方法捕获成蚊,经形态学鉴定后麻醉处死,密封干燥,带回实验室-20℃冻存备用,采用混合样本法随机抽取10只多斑按蚊复合体为一份混合标本,提取蚊虫DNA。根据文献采用巢氏PCR扩增疟原虫小亚单位核糖体脱氧核糖核酸(SSUrDNA),并对阳性结果克隆测序,比对证实。结果共捕获按蚊5345只,其中多斑按蚊复合体5190只,带足按蚊155只,提取的360份多斑按蚊复合体混合样本DNA中发现子孢子阳性扩增样品2份,种型鉴定2份阳性混合样本均为伪威氏按蚊,PCR产物经克隆测序,NCBIBLAST同源性比对证实为疟原虫SSurDNA基因片段。结论多斑按蚊复合体中的伪威氏按蚊为西藏林芝疟疾流行区的传疟媒介。

Nested PCR identified the malaria vector in Tibet malaria endemic area

To find the malaria vectors in malaria-epidemic area in Linzhi district,Tibet,three villages with higher malaria incidence were selected as investigation spots.Human-baited traps,cow-baited traps,CDC light traps and morning collection were adopted to collect mosquitoes.Mosquitoes were killed after identified as Anopheles maculatus complex and stored with desiccant at-20℃.DNA was extracted from mixed mosquito sample.SSU rDNA of sporozoites was amplified according to reference,and the positive products of PCR were cloned,sequenced and blasted for confirmation.Of 5 190 out of 5 345 Anopheles mosquitoes were Anopheles maculatus complex and the remainders were Anopheles peditaeniatus.Two positive samples were found in 360 mixed Anopheles maculatus complex DNA samples,and identified as Anopheles pseudowillmori by species identification method.It＇s indicated that Anopheles pseudowillmori of Anopheles maculatus complex is the malaria vector in Linzhi malaria-endemic area.