Rodrigues Marina Silva, Lima Luciana, Xavier Samanta Cristina das Chagas, Herrera Heitor Miraglia, Rocha Fabiana Lopes, Roque André Luiz Rodrigues, Teixeira Marta Maria Geraldes, Jansen Ana Maria
Laboratório de Biologia de Tripanosomatídeos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
Int J Parasitol Parasites Wildl. 2019 Feb 14;8:171-181. doi: 10.1016/j.ijppaw.2019.02.004. eCollection 2019 Apr.
spp. infection in wild mammals is detected mainly through parasitological tests that usually display low sensitivity. We propose the use of DNA extracted directly from blood clots (BC), which are neglected sources of DNA for diagnosis and identification of spp. This approach followed by nested PCR targeting the 18S SSU rDNA demonstrated to be sensitive and suitable to evaluate the diversity of trypanosomes infecting sylvatic mammals, including subpatent and mixed infections. Infection was detected in 95/120 (79.2%) samples from bats, carnivores and marsupials that included negative serological and hemoculture testing mammals. Thirteen spp. or Molecular Operational Taxonomic Units (MOTUs) were identified, including two new MOTUs. The high diversity of trypanosomes species and MOTUs infecting bats and marsupials showed that these hosts can be considered as bio-accumulators of spp., with specimens of spp. displaying the highest trypanosome diversity. The use of blood clots allowed direct access to non-culturable parasites, mixed infections, besides bypassing the selective pressure on the parasites inherent to cultivation procedures. was the species found infecting the highest number of individuals, followed by Positive PCR for was observed in 16 seronegative individuals and 30 individuals with negative hemocultures. Also, , previously found only in rodents, showed to be capable of infecting bats and marsupials. This finding makes it clear that some species of are more generalist than previously thought. Molecular diagnosis using nested PCR from DNA extracted from BC allowed the increase of the knowledge about host-spectrum and distribution of spp. and allowed the identification of new MOTUs.
野生哺乳动物锥虫感染主要通过寄生虫学检测来发现,而这些检测通常灵敏度较低。我们建议使用直接从血凝块(BC)中提取的DNA,血凝块是诊断和鉴定锥虫属时被忽视的DNA来源。这种方法随后进行针对18S小亚基核糖体DNA(SSU rDNA)的巢式PCR,结果表明该方法灵敏且适合评估感染野生哺乳动物的锥虫多样性,包括亚临床感染和混合感染。在来自蝙蝠、食肉动物和有袋动物的120个样本中的95个(79.2%)检测到感染,这些样本包括血清学和血培养检测呈阴性的哺乳动物。鉴定出13种锥虫或分子操作分类单元(MOTUs),包括两个新的MOTUs。感染蝙蝠和有袋动物的锥虫物种和MOTUs具有高度多样性,这表明这些宿主可被视为锥虫属的生物蓄积宿主,其中锥虫属样本显示出最高的锥虫多样性。使用血凝块可以直接获取不可培养的寄生虫、混合感染,还能绕过培养程序对寄生虫固有的选择压力。是感染个体数量最多的物种,其次是在16例血清学阴性个体和30例血培养阴性个体中观察到针对的阳性PCR结果。此外,之前仅在啮齿动物中发现的,显示出能够感染蝙蝠和有袋动物。这一发现清楚地表明,某些锥虫物种比之前认为的更具普遍性。使用从BC提取的DNA进行巢式PCR的分子诊断增加了我们对锥虫属宿主谱和分布的了解,并有助于鉴定新的MOTUs。