Institut de Recherche en Sciences de la Santé-Direction Régionale de l'Ouest, Bobo Dioulasso, Burkina Faso.
Malar J. 2013 Jan 2;12:2. doi: 10.1186/1475-2875-12-2.
The question whether Plasmodium falciparum infection affects the fitness of mosquito vectors remains open. A hurdle for resolving this question is the lack of appropriate control, non-infected mosquitoes that can be compared to the infected ones. It was shown recently that heating P. falciparum gametocyte-infected blood before feeding by malaria vectors inhibits the infection. Therefore, the same source of gametocyte-infected blood could be divided in two parts, one heated, serving as the control, the other unheated, allowing the comparison of infected and uninfected mosquitoes which fed on exactly the same blood otherwise. However, before using this method for characterizing the cost of infection to mosquitoes, it is necessary to establish whether feeding on previously heated blood affects the survival and fecundity of mosquito females.
Anopheles gambiae M molecular form females were exposed to heated versus non-heated, parasite-free human blood to mimic blood meal on non-infectious versus infectious gametocyte-containing blood. Life history traits of mosquito females fed on blood that was heat-treated or not were then compared.
The results reveal that heat treatment of the blood did not affect the survival and fecundity of mosquito females. Consistently, blood heat treatment did not affect the quantity of blood ingested.
The study indicates that heat inactivation of gametocyte-infected blood will only inhibit mosquito infection and that this method is suitable for quantifying the fitness cost incurred by mosquitoes upon infection by P. falciparum.
疟原虫感染是否会影响蚊子媒介的适应性仍是一个悬而未决的问题。解决这个问题的一个障碍是缺乏合适的对照，即没有被感染的蚊子可以与感染的蚊子进行比较。最近的研究表明，在疟蚊吸食疟原虫配子体感染的血液之前对其进行加热，可以抑制感染。因此，可以将相同来源的配子体感染血液分为两部分，一部分加热作为对照，另一部分不加热，这样就可以对吸食相同血液但感染和未感染的蚊子进行比较。然而，在将这种方法用于描述感染对蚊子的成本之前，有必要确定以前加热的血液是否会影响雌性蚊子的生存和繁殖力。
用加热和未加热的、不含寄生虫的人血来模拟吸食不含感染性配子体的血液和含有感染性配子体的血液，让冈比亚按蚊 M 型雌性个体接触这两种血液。然后比较吸食经过热处理或未经热处理的血液的蚊子雌性个体的生活史特征。
结果表明，血液的热处理并没有影响蚊子雌性个体的生存和繁殖力。一致地，血液的热处理也没有影响蚊子摄入的血量。
本研究表明，感染的配子体血液的热失活只会抑制蚊子的感染，并且这种方法适用于量化疟原虫感染对蚊子适应性造成的成本。
