Departamento de Ecología de Humedales, Estación Biológica de Doñana (EBD-CSIC), Seville, Spain.
Parasit Vectors. 2013 Jul 15;6:208. doi: 10.1186/1756-3305-6-208.
Blood-sucking flying insects play a key role in the transmission of pathogens of vector-borne diseases. However, at least for the case of avian malaria parasites, the vast majority of studies focus on the interaction between parasites and vertebrate hosts, but there is a lack of information regarding the interaction between the parasites and the insect vectors. Here, we identified the presence of malaria and malaria-like parasite lineages harbored by the potential vector Culicoides circumscriptus (Kieffer). Also, we identified some nodes of the transmission network connecting parasite lineages, potential insect vectors and avian hosts by comparing Haemoproteus and Plasmodium lineages isolated from insects with those infecting wild birds in this and previous studies.
Using a molecular approach, we analysed the presence of blood parasites in a total of 97 biting midges trapped in the Doñana National Park (SW Spain) and surrounding areas. Also, 123 blood samples from 11 bird species were analyzed for the presence of blood parasite infections. Blood parasites Haemoproteus and Plasmodium were identified by amplification of a 478 bp fragment of the mitochondrial cytochrome b gen.
Thirteen biting midges harboured blood parasites including six Haemoproteus and two Plasmodium lineages, supporting the potential role of these insects on parasite transmission. Moreover, ten (8.1%) birds carried blood parasites. Seven Plasmodium and one Haemoproteus lineages were isolated from birds. Overall, six new Haemoproteus lineages were described in this study. Also, we identified the transmission networks of some blood parasites. Two Haemoproteus lineages, hCIRCUM03 and GAGLA03, were identical to those isolated from Corvus monedula in southern Spain and Garrulus glandarius in Bulgaria, respectively. Furthermore, the new Haemoproteus lineage hCIRCUM05 showed a 99% similarity with a lineage found infecting captive penguins in Japan.
The comparison of the parasite lineages isolated in this study with those previously found infecting birds allowed us to identify some potential nodes in the transmission network of avian blood parasite lineages. These results highlight the complexity of the transmission networks of blood parasites in the wild that may involve a high diversity of susceptible birds and insect vectors.
吸血飞虫在传播病媒传播疾病的病原体方面起着关键作用。然而，至少就禽疟原虫而言，绝大多数研究都集中在寄生虫与脊椎动物宿主之间的相互作用上，但缺乏有关寄生虫与昆虫媒介之间相互作用的信息。在这里，我们确定了潜在媒介库蠓（Kieffer）所携带的疟原虫和类似疟原虫寄生虫谱系的存在。此外，我们通过比较从昆虫中分离出的 Haemoproteus 和 Plasmodium 谱系与本研究和先前研究中感染野生鸟类的谱系，确定了连接寄生虫谱系、潜在昆虫媒介和鸟类宿主的传播网络中的一些节点。
我们使用分子方法分析了总共 97 只在多纳纳国家公园（西班牙西南部）及其周边地区捕获的吸血蚊中血液寄生虫的存在。此外，还分析了 11 种鸟类的 123 份血液样本，以检测血液寄生虫感染情况。通过扩增线粒体细胞色素 b 基因的 478 bp 片段，鉴定血液寄生虫 Haemoproteus 和 Plasmodium。
13 只吸血蚊携带血液寄生虫，包括 6 种 Haemoproteus 和 2 种 Plasmodium 谱系，这支持了这些昆虫在寄生虫传播中的潜在作用。此外，有 10 只（8.1%）鸟类携带血液寄生虫。从鸟类中分离出 7 种 Plasmodium 和 1 种 Haemoproteus 谱系。总的来说，本研究中描述了 6 种新的 Haemoproteus 谱系。此外，我们还确定了一些血液寄生虫的传播网络。两种 Haemoproteus 谱系 hCIRCUM03 和 GAGLA03 分别与在西班牙南部感染鸦科鸟类的寄生虫和在保加利亚感染欧亚红松鼠的寄生虫相同。此外，新的 Haemoproteus 谱系 hCIRCUM05 与在日本感染圈养企鹅的寄生虫具有 99%的相似性。
将本研究中分离出的寄生虫谱系与以前发现感染鸟类的寄生虫谱系进行比较，使我们能够确定一些鸟类血液寄生虫谱系传播网络中的潜在节点。这些结果突出了野生环境中血液寄生虫传播网络的复杂性，其中可能涉及到大量易感染的鸟类和昆虫媒介。
