Evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity
Evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity
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DOI：
10.1186/1475-2875-7-248
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发表时间：
2008-12-02
期刊：
影响因子：
3
通讯作者：
Doumbo, Ogobara K.
中科院分区：
文献类型：
--
作者：
Diallo, Mouctar;Toure, Abdoulaye M.;Doumbo, Ogobara K.
背景：疟疾寄生虫对蚊子的感染性已通过多种方式和环境进行了测量，包括直接喂养和/或膜喂养从随机选择的或配子体志愿者收集的血液。冈比亚按蚊 s.l 是班库马纳恶性疟原虫传播的主要媒介，约占实验室结果的 90%，而三日疟原虫和卵形疟原虫合计仅占 10%。 材料和方法：1996 年 8 月至 1998 年 12 月期间，比较了直接喂养法和膜饲法，以了解儿童和青少年配子体携带者对按蚊的感染性在马里的 Bancoumana 村。通过使用吉姆萨染色的厚血涂片对 30 个家庭的成员进行筛选，每月两次招募配子体携带者。来自 Bancoumana 的雌性野生蚊子发出的 FI 代蚊子在受控昆虫条件下饲养，并在巴马科的实验室中喂食 5% 的糖溶液，直到喂食日，在喂食实验前 12 小时让它们挨饿。这些FI代蚊子被分为两组，一组直接用配子体携带者喂养，另一组采用膜喂养法喂养。 结果：372只恶性疟原虫配子体携带者的结果显示，4-9岁的儿童比青少年更具传染性（p = 0.039），特别是在雨季。来自 35 个携带者的数据显示，与用于膜喂养的蚊子相比，用于直接喂养的蚊子进食的可能性大约高 1.5 倍 (p < 0.001)，如果它们进食则被感染的可能性高出两倍 (p < 0.001)。总体而言，直接喂养的传染性大约是膜喂养的三倍（p < 0.001）。结论：虽然膜喂养的传染性强度较低，但它可以替代直接喂养来评估候选疟疾疫苗的传播阻断活性。未来试验方法的优化将涉及使用比直接喂食多三倍的蚊子。
Background: Malaria parasite infectivity to mosquitoes has been measured in a variety of ways and setting, includind direct feeds of and/or membrane feeding blood collected from randomly selected or gametocytemic volunteers. Anopheles gambiae s.l is the main vector responsible of Plasmodium falciparum transmission in Bancoumana and represents about 90% of the laboratory findings, whereas Plasmodium malariae and Plasmodium ovale together represent only 10%.Materials and methods: Between August 1996 and December 1998, direct and membrane feeding methods were compared for the infectivity of children and adolescent gametocyte carriers to anopheline mosquitoes in the village of Bancoumana in Mali. Gametocyte carriers were recruited twice a month through a screening of members of 30 families using Giemsa-stained thick blood smears. FI generation mosquitoes issued from individual female wild mosquitoes from Bancoumana were reared in a controlled insectary conditions and fed 5% sugar solution in the laboratory in Bamako, until the feeding day when they are starved 12 hours before the feeding experiment. These FI generation mosquitoes were divided in two groups, one group fed directly on gametocyte carriers and the other fed using membrane feeding method.Results: Results from 372 Plasmodium falciparum gametocyte carriers showed that children aged 4-9 years were more infectious than adolescents (p = 0.039), especially during the rainy season. Data from 35 carriers showed that mosquitoes which were used for direct feeding were about 1.5 times more likely to feed (p < 0.001) and two times more likely to become infected, if they fed (p < 0.001), than were those which were used for membrane feeding. Overall, infectivity was about three-times higher for direct feeding than for membrane feeding (p < 0.001).Conclusion: Although intensity of infectivity was lower for membrane feeding, it could be a surrogate to direct feeding for evaluating transmission-blocking activity of candidate malaria vaccines. An optimization of the method for future trials would involve using about three-times more mosquitoes than would be used for direct feeding.