Caracterização morfológica e molecular de Plasmodium spp. (Apicomplexa, Haemosporida) em aves de fragmentos da Mata Atlântica

Abstract

Plasmodium spp. are haemosporidian protozoa that cause avian malaria. These parasites alternate between dipteran bloodsucking of Culicidae family and vertebrate hosts in their life cycle and have been recorded in birds in many parts of the world. In Brazil, despite the great diversity of birds and vectors species, few studies are conducted with haemosporidian in the Atlantic Forest region. In this study, blood samples from 90 birds of four species of Turdus genus, collected in Atlantic Forest fragments of Minas Gerais and 80 birds of 15 species kept in captivity in southeastern Brazil were analyzed for the presence of Plasmodium spp. by microscopic analysis and sequencing of the mitochondrial gene cytochrome oxidase b (cyt b). In total, 58 birds of genus Turdus were positively infected with Plasmodium unalis, identified based on both methods, morphological and molecular, being recorded four new hosts for this parasite. The description of this haemosporidian was expanded and some features differ from the original description. Seven new lineages of P. unalis were added to databases. The TLJB34 and TLSB1096 lineages grouped in a separate clade with sequences of Plasmodium spp., being more distant in relation to the other obtained in the present study, with 3% of genetic divergence. Regarding the birds kept in captivity, among the 61 sampled, in nine were found the species Plasmodium paranucleophilum (prevalence 14.75% and mean parasitemia 0.58%), and the morphological and morphometric descriptions of this parasite were extended. And among the 19 birds of the genus Ramphastos sampled, in five was identified the species Plasmodium nucleophilum (prevalence 26.31% and mean parasitemia 0.04%). In phylogenetic analyzes, the two species formed separate clades with high support value, and the mean genetic divergence of P. paranucleophilum regarding P. nucleophilum was 2.48%. The literature review and the results of this study showed that P. nucleophilum species have a higher number of records in the Americas and appear to have low specificity as the hosts. This study provides new morphological and molecular data on birds haemosporidian of Brazil, confirms the importance of integrative taxonomy and the use of molecular and morphological approaches combined to identify and characterize species of avian haemosporidian and also emphasizes the need to expand studies in country, since the true diversity of haemosporidian aviaries is still little known and given the enormous diversity of vectors and species of Brazilian birds, there may be many species of these blood parasites not described yet