应用多重PCR法分析西藏察隅疟疾流行区按蚊吸血习性

目的用多重PCR法分析西藏疟疾流行区察隅县常见按蚊的吸血习性,为下一步研究传疟媒介提供参考。方法2011年7~8月选择察隅县不同生态环境的3个自然村(日玛村、塔玛村和京都村),每个村在人房和畜舍选择8个点,采用诱蚊灯全通宵(20∶00至次日08∶00)诱捕法捕捉按蚊,次日清晨收集诱捕的蚊虫,经形态学鉴定蚊种,分析按蚊组成。收集饱血按蚊,分别提取单只蚊胃血的DNA,采用基于不同动物mtDNA-cytb序列差异的多重PCR法鉴定各蚊胃血源,计算人血指数,分析按蚊的吸血习性。结果共捕获按蚊1 442只,经形态学鉴定,多斑按蚊种团占99.6%(1 436/1 442),带足按蚊和腹簇按蚊占0.4%(6/1442)。多斑按蚊种团中,伪威氏按蚊占85.5%(1228/1436),威氏按蚊占14.5%(208/1 436)。用多重PCR检测202只多斑按蚊种团(伪威氏按蚊188只和威氏按蚊14只)的饱血蚊胃血,结果显示,伪威氏按蚊兼吸牛/猪血和人血,人血指数为0.35,威氏按蚊吸食猪血和人血,人血指数为0.29。结论西藏察隅县2种常见按蚊(伪威氏按蚊和威氏按蚊)均兼吸人畜血,伪威氏按蚊的人血指数较高。

Investigation on blood-sucking habit of anopheles (Diptera:Culicidae) using multiplex polymerase chain reaction in malaria-endemic area of Chayu County, Tibet

Objective To determine the blood-sucking habit of anopheline by mosquitoes bloodmeal identification in malaria endemic area Chayu County,Tibet Autonomous Region.Methods Three villages with different bio-enviroments were selected as the investigation spots.Light traps were set up outdoor and in livestock sheds from sunset(20 ∶ 00) to sunrise(8 ∶ 00) in 3-4 consecutive nights to collect mosquitoes.The trapped anophelines were counted and identified according to morphological criteria and multiple PCR method.A PCR-based methodology according to the mtDNA-cytb variations was used in different mammal hosts to identify bloodmeal sources in engorged mosquitoes.The human blood index(HBI) was assessed to determine the range of hosts.Results Among 1 442 anopheline mosquitoes collected by 108 lighttraps on 13 nights.1 436(99.6%) belonged to Anopheles maculatus complex,with 85.5% An.pseudowillmori and 14.5% An.willmori.Positive bloodmeal identification was found from 168(83%) of 202 field-collected engorged mosquitoes.The crude HBI of An.pseudowillmori and An.willmori were 0.35 and 0.29,respectively.Conclusion An.pseudowillmori and An.willmori are both zoophilic and anthropophilic,and An.pseudowillmori shows a higher HBI.