Zehtindjiev Pavel, Ilieva Mihaela, Westerdahl Helena, Hansson Bengt, Valkiūnas Gediminas, Bensch Staffan
Institute of Zoology, Bulgarian Academy of Sciences, Boulevard, Tzar Osvoboditel 1, 1000 Sofia, Bulgaria.
Exp Parasitol. 2008 May;119(1):99-110. doi: 10.1016/j.exppara.2007.12.018. Epub 2008 Jan 13.
Little is known about the development of infection of malaria parasites of the genus Plasmodium in wild birds. We used qPCR, targeting specific mitochondrial lineages of Plasmodium ashfordi (GRW2) and Plasmodium relictum (GRW4), to monitor changes in intensities of parasitemia in captive great reed warblers Acrocephalus arundinaceus from summer to spring. The study involved both naturally infected adults and experimentally infected juveniles. The experiment demonstrated that P. ashfordi and P. relictum lineages differ substantially in several life-history traits (e.g. prepatent period and dynamics of parasitemia) and that individual hosts show substantial differences in responses to these infections. The intensity of parasitemia of lineages in mixed infections co-varied positively, suggesting a control mechanism by the host that is general across the parasite lineages. The intensity of parasitemia for individual hosts was highly repeatable suggesting variation between the host individuals in their genetic or acquired control of the infections. In future studies, care must be taken to avoid mixed infections in wild caught donors, and when possible use mosquitoes for the experiments as inoculation of infectious blood ignores important initial stages of the contact between the bird and the parasite.
关于疟原虫属疟原虫在野生鸟类体内的感染发展情况，人们了解甚少。我们使用定量聚合酶链反应（qPCR），针对阿氏疟原虫（GRW2）和残疟原虫（GRW4）的特定线粒体谱系，来监测圈养大苇莺从夏季到春季期间疟原虫血症强度的变化。该研究涉及自然感染的成年鸟和实验感染的幼鸟。实验表明，阿氏疟原虫和残疟原虫谱系在几个生活史特征（如潜伏期和疟原虫血症动态）上有很大差异，而且个体宿主对这些感染的反应也有很大差异。混合感染中各谱系的疟原虫血症强度呈正相关变化，这表明宿主存在一种对各寄生虫谱系普遍适用的控制机制。个体宿主的疟原虫血症强度具有高度重复性，这表明宿主个体在对感染的遗传或后天控制方面存在差异。在未来的研究中，必须注意避免在野外捕获的供体中出现混合感染，并且尽可能使用蚊子进行实验，因为接种感染性血液忽略了鸟类与寄生虫接触的重要初始阶段。
