Departamento de Medicina Veterinária Preventiva E Saúde Animal, Faculdade de Medicina Veterinária E Zootecnia, Universidade de São Paulo, São Paulo, Brazil.
Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
Parasit Vectors. 2022 Mar 15;15(1):87. doi: 10.1186/s13071-022-05216-8.
Small mammals (rodents and marsupials) have been poorly explored for the occurrence of apicomplexan (genus Hepatozoon and genera of the order Piroplasmorida) and Anaplasmataceae agents in Brazil. Thus, this study investigated the occurrence of Hepatozoon spp., Piroplasmorida, and Anaplasmataceae agents in small mammals in seven forest fragments in Brazil.
During 2015-2018, small mammals were captured in six forest fragments in the State of São Paulo (Cerrado and Atlantic Forest biomes) and one fragment in the State of Mato Grosso do Sul (Pantanal biome). Mammal blood, liver, spleen, and lung samples were tested molecularly for the presence of DNA of Hepatozoon, Piroplasmorida, and Anaplasmataceae agents.
A total of 524 mammals were captured, comprising seven species of marsupials, 14 rodents, two carnivores, and one Cingulata. Four novel haplotypes (1, 2, 3, 4) of Hepatozoon spp. were detected in small mammals from different biomes. In São Paulo state, haplotype 1 was detected in rodents from Cerrado and a transition area of Cerrado and Atlantic Forest biomes, whereas haplotype 2 was detected in rodents from the Atlantic Forest biome. On the other hand, haplotypes 3 and 4 were restricted to rodents and marsupials, respectively, from the Pantanal biome of Mato Grosso do Sul. No host species shared more than one haplotype. Despite these distinct geographical and host associations, our phylogenetic analyses indicated that the four Hepatozoon haplotypes belonged to the same clade that contained nearly all haplotypes previously reported on rodents and marsupials, in addition to several reptile-associated haplotypes from different parts of the world. No mammal samples yielded detectable DNA of Piroplasmorida agents. On the other hand, the Anaplasmataceae-targeted polymerase chain reaction (PCR) assay amplified a sequence 100% identical to the Wolbachia pipientis endosymbiont of the rodent filarid Litomosoides galizai.
We report a variety of Hepatozoon haplotypes associated with small mammals in three Brazilian biomes: Cerrado, Atlantic Forest, and Pantanal. Through phylogenetic analyses, the Hepatozoon agents grouped in the rodent-marsupial-reptile large clade of Hepatozoon spp. from the world. The detection of a W. pipientis associated with the rodent filarid L. galizai indicates that the rodent was infected by filarial nematodes.
在巴西，小型哺乳动物（啮齿动物和有袋目动物）中锥体虫（属 Hepatozoon 和属 Piroplasmorida 目）和立克次体科的发生情况研究甚少。因此，本研究调查了 7 个森林片段中小型哺乳动物中 Hepatozoon 种、Piroplasmorida 和立克次体科的发生情况。
在 2015-2018 年期间，在巴西的 6 个森林片段（塞拉多和大西洋森林生物群）和 1 个南马托格罗索州（潘塔纳尔生物群）的片段中捕获了小型哺乳动物。对哺乳动物的血液、肝脏、脾脏和肺样本进行了分子检测，以检测 Hepatozoon、Piroplasmorida 和立克次体科的 DNA。
共捕获了 524 只哺乳动物，包括 7 种有袋目动物、14 种啮齿动物、2 种食肉动物和 1 种贫齿目动物。在来自不同生物群的小型哺乳动物中检测到了 4 种新的 Hepatozoon 种单倍型（1、2、3、4）。在圣保罗州，单倍型 1 存在于塞拉多和塞拉多与大西洋森林生物群过渡区的啮齿动物中，而单倍型 2 存在于大西洋森林生物群的啮齿动物中。另一方面，单倍型 3 和 4分别局限于来自南马托格罗索州潘塔纳尔生物群的啮齿动物和有袋目动物。没有一种宿主物种共享一种以上的单倍型。尽管存在这些明显的地理和宿主关联，但我们的系统发育分析表明，这 4 种 Hepatozoon 单倍型属于同一进化枝，其中包含了以前在啮齿动物和有袋目动物中报道的几乎所有单倍型，以及来自世界不同地区的几种与爬行动物相关的单倍型。没有哺乳动物样本可检测到 Piroplasmorida 病原体的 DNA。另一方面，针对立克次体科的聚合酶链反应（PCR）检测扩增出的序列与来自啮齿目 filarid Litomosoides galizai 的 Wolbachia pipientis 共生体完全相同。
我们报告了三种巴西生物群（塞拉多、大西洋森林和潘塔纳尔）中小型哺乳动物的各种 Hepatozoon 单倍型。通过系统发育分析，Hepatozoon 病原体在世界范围内的啮齿动物-有袋目动物-爬行动物大进化枝中分组。检测到与啮齿目 filarid L. galizai 相关的 W. pipientis 表明，啮齿动物感染了丝虫。
