Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho" (FCAV/UNESP), Jaboticabal, SP, Brazil.
Laboratório de Biologia de Tripanosomatídeos, Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, RJ, Brazil.
Sci Rep. 2019 Jul 12;9(1):10122. doi: 10.1038/s41598-019-46662-2.
Hepatozoon spp. are Apicomplexan protozoa that parasitize a wide diversity of vertebrate hosts. In Brazil, few studies have reported the occurrence of Hepatozoon spp. in rodent species. Additionally, an evaluation of the population structure and distribution of Hepatozoon species over several Brazilian biomes has not yet been performed. The present work aimed to investigate the genetic diversity of Hepatozoon spp. in rodents from 31 genera sampled in five Brazilian biomes. Samples were submitted to PCR assays for Hepatozoon spp. targeting two regions of the 18S rRNA gene. Infection by Hepatozoon spp. was detected in 195 (42.2%) rodents comprising 24 genera. Phylogenetic analyses of 18S rRNA sequences grouped all sequences in the clade of Hepatozoon spp. previously detected in rodents and reptiles, apart from those detected in domestic/wild carnivores. These data raise two non-exclusive hypotheses: (i) rodents play an important role as intermediate or paratenic hosts for Hepatozoon infections in reptiles; and (ii) rodents do not seem to participate in the epidemiology of Hepatozoon infections of domestic/wild canids and felids in Brazil. TCS analyses performed with available 18S rRNA Hepatozoon sequences detected in rodents from Brazil showed the occurrence of six haplotypes, which were distributed in two large groups: one from rodents inhabiting the coastal region of Brazil and Mato Grosso state, and another from rodents from the central region of the country. A wide survey of the South American territory will help to elucidate the evolutionary history of Hepatozoon spp. parasitizing Rodentia in the American continent.
肝孢虫属是寄生在广泛多样性的脊椎动物宿主中的顶复门原生动物。在巴西，少数研究报告了啮齿动物中肝孢虫属的发生。此外，还没有对几个巴西生物群落中的肝孢虫种的种群结构和分布进行评估。本研究旨在调查来自五个巴西生物群落中 31 个属的啮齿动物中肝孢虫属的遗传多样性。对针对 18S rRNA 基因的两个区域的 Hepatozoon spp. 的 PCR 检测的样本进行了分析。在包括 24 个属的 195 只（42.2%）啮齿动物中检测到了肝孢虫属的感染。18S rRNA 序列的系统发育分析将所有序列分组到先前在啮齿动物和爬行动物中检测到的肝孢虫属的分支中，除了在家养/野生食肉动物中检测到的序列之外。这些数据提出了两个非排他性假设：（i）啮齿动物在爬行动物的肝孢虫感染中作为中间或副宿主起着重要作用；（ii）啮齿动物似乎不参与巴西家养/野生犬科和猫科动物的肝孢虫感染的流行病学。用在巴西的啮齿动物中检测到的可用的 18S rRNA Hepatozoon 序列进行的 TCS 分析检测到了六个单倍型，这些单倍型分布在两个大组中：一组来自巴西沿海地区和马托格罗索州的啮齿动物，另一组来自该国中部地区的啮齿动物。对南美洲领土的广泛调查将有助于阐明寄生在美洲大陆啮齿动物中的肝孢虫属的进化历史。
