Experimental study of newly described avian malaria parasite Plasmodium (Novyella) collidatum n. sp., genetic lineage pFANTAIL01 obtained from South Asian migrant bird
Abstract BackgroundAvian malaria parasites are common and worldwide distributed microorganisms parasitizing erythrocytes and various tissues of the birds. These parasites are known to infect birds of different taxa and be the cause of the bird’s deaths in wildlife and captivity. A particular interest possesses the species of parasites with the ability to colonize new territories and infect local non-migratory birds. This scenario is likely in temperate zones of Europe because of the present climate change and its contribution to the spreading of southern origin vectors which can be involved in the transmission of malaria parasites. In the present study, a tropical Plasmodium parasite from a naturally infected long-distance migrant bird was isolated and tested for its ability to develop in common species of mosquitoes and European short-distance migrant bird. MethodsPlasmodium sp. (pFANTAIL01) was isolated from the naturally infected Common rosefinch, Carpodacus erythrinus. The parasite was described based on the morphological features of its blood stages, the partial mitochondrial cytochrome b gene and development after experimental infection of birds and mosquitoes. The parasite was inoculated into Eurasian siskins, Carduelis spinus. Parasitemia, hematocrit value and weight of birds were monitored. At the end of the survey, internal organs were collected to study exoerythrocytic stages of this parasite. Experimental infection of mosquitoes Culex pipiens pipiens form molestus and C. quinquefasciatus was applied to study sporogonic development of the parasite.ResultsBased on morphological features, the new parasite was described as Plasmodium collidatum n. sp. and attributed to subgenus Novyella. It was revealed that the obtained pFANTAIL01 lineage is a generalist parasite infecting a wide range of avian hosts and most likely is transmitted in South and Southeast (SE) Asia and Oceania. In Europe this strain was recorded only in adult migratory birds wintering in South Asia. This parasite developed high parasitemia in experimentally infected siskins and caused 25% mortality. Exoerythrocytic stages of pFANTAIL01 were found in the lungs, liver, spleen and kidney of the deceased birds. Sporogonic development did not occur in C. p. p. f. molestus and C. quinquefasciatus mosquitoes.ConclusionPlasmodium collidatum is a highly virulent for Eurasian siskin and completes its development in these birds, which can be considered as a potential vertebrate host if the transmission of the infection starts occurring in Europe and temperate zones.