Oliveira Luísa, Dias Roberto Júnio Pedroso, Rossi Mariana F, D'Agosto Marta, Santos Huarrisson A
Department of Animal Parasitology, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil.
Department of Zoology (LabProto), Biological Sciences Institute, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil.
Parasitol Res. 2020 Dec;119(12):4033-4047. doi: 10.1007/s00436-020-06908-9. Epub 2020 Oct 8.
Haemoproteus spp. and Plasmodium spp. are blood parasites that occur in birds worldwide. Identifying the species within this group is complex, especially in wild birds that present low parasitemia when captured, making morphological identification very difficult. Thus, the use of alternative tools to identify species may be useful in the elucidation of the distribution of parasites that circulate in bird populations. The objectives of this study were to determine the prevalence and parasitemia of the genera Plasmodium and Haemoproteus in Tachyphonus coronatus in the Atlantic Forest, Brazil, and to evaluate the molecular diversity, geographic distribution, and specificity of these parasites based on coalescent species delimitation methods. Microscopic analysis, PCR, cyt b gene sequencing, phylogenetic analysis and coalescent species delimitation using single-locus algorithms were performed (Poisson tree process (PTP) and multi-rate Poisson tree process (MPTP) methods). The analyses were performed in 117 avian host individuals. The prevalence was 55.5% for Plasmodium and 1.7% for Haemoproteus, with a mean parasitemia of 0.06%. Twenty-five Plasmodium and two Haemoproteus lineages were recovered. The MPTP method recovered seven different evolutionarily significant units (ESUs) of Plasmodium and one of Haemoproteus, whereas PTP presented fourteen ESUs of Plasmodium and one of Haemoproteus. The MPTP was more consistent with current taxonomy, while PTP overestimated the number of lineages. These ESUs are widely distributed and have already been found in 22 orders of birds that, all together, inhabit every continent, except Antarctica. The computational methods of species delimitation proved to be effective in cases where the classification of Haemosporida based just on morphology is insufficient.
血变原虫属和疟原虫属是广泛存在于世界各地鸟类中的血液寄生虫。识别该类群中的物种很复杂，尤其是在捕获时寄生虫血症水平较低的野生鸟类中，这使得形态学鉴定非常困难。因此，使用替代工具来识别物种可能有助于阐明鸟类种群中传播的寄生虫的分布情况。本研究的目的是确定巴西大西洋森林中冠红嘴雀体内疟原虫属和血变原虫属的流行率和寄生虫血症，并基于溯祖物种界定方法评估这些寄生虫的分子多样性、地理分布和特异性。进行了显微镜分析、聚合酶链反应（PCR）、细胞色素b基因测序、系统发育分析以及使用单基因座算法的溯祖物种界定（泊松树过程（PTP）和多速率泊松树过程（MPTP）方法）。对117只鸟类宿主个体进行了分析。疟原虫的流行率为55.5%，血变原虫为1.7%，平均寄生虫血症为0.06%。共鉴定出25个疟原虫谱系和2个血变原虫谱系。MPTP方法识别出7个不同的疟原虫进化显著单元（ESU）和1个血变原虫ESU，而PTP方法识别出14个疟原虫ESU和1个血变原虫ESU。MPTP方法与当前分类学更一致，而PTP方法高估了谱系数量。这些ESU分布广泛，已在22个鸟类目中发现，这些鸟类共同栖息在除南极洲以外的各大洲。在仅基于形态学对血孢子虫进行分类不足的情况下，物种界定的计算方法被证明是有效的。
