Laboratorio de Biología Molecular de la Enfermedad de Chagas, INGEBI-CONICET, Buenos Aires, Argentina.
Int J Parasitol. 2010 Dec;40(14):1599-607. doi: 10.1016/j.ijpara.2010.06.006. Epub 2010 Jul 27.
The intergenic region of spliced-leader (SL-IR) genes from 105 Trypanosoma cruzi I (Tc I) infected biological samples, culture isolates and stocks from 11 endemic countries, from Argentina to the USA were characterised, allowing identification of 76 genotypes with 54 polymorphic sites from 123 aligned sequences. On the basis of the microsatellite motif proposed by Herrera et al. (2007) to define four haplotypes in Colombia, we could classify these genotypes into four distinct Tc I SL-IR groups, three corresponding to the former haplotypes Ia (11 genotypes), Ib (11 genotypes) and Id (35 genotypes); and one novel group, Ie (19 genotypes). Genotypes harbouring the Tc Ic motif were not detected in our study. Tc Ia was associated with domestic cycles in southern and northern South America and sylvatic cycles in Central and North America. Tc Ib was found in all transmission cycles from Colombia. Tc Id was identified in all transmission cycles from Argentina and Colombia, including Chagas cardiomyopathy patients, sylvatic Brazilian samples and human cases from French Guiana, Panama and Venezuela. Tc Ie gathered five samples from domestic Triatoma infestans from northern Argentina, nine samples from wild Mepraia spinolai and Mepraia gajardoi and two chagasic patients from Chile and one from a Bolivian patient with chagasic reactivation. Mixed infections by Tc Ia+Tc Id, Tc Ia+Tc Ie and Tc Id+Tc Ie were detected in vector faeces and isolates from human and vector samples. In addition, Tc Ia and Tc Id were identified in different tissues from a heart transplanted Chagas cardiomyopathy patient with reactivation, denoting histotropism. Trypanosoma cruzi I SL-IR genotypes from parasites infecting Triatoma gerstaeckeri and Didelphis virginiana from USA, T. infestans from Paraguay, Rhodnius nasutus and Rhodnius neglectus from Brazil and M. spinolai and M. gajardoi from Chile are to our knowledge described for the first time.
从 105 个感染了克氏锥虫 I（Tc I）的生物样本、培养物和库存中，分析了来自 11 个流行国家（从阿根廷到美国）的拼接领导者（SL-IR）基因的基因间区，确定了 76 种基因型，在 123 个对齐序列中有 54 个多态性位点。基于 Herrera 等人（2007 年）提出的微卫星基序，将哥伦比亚的 4 种单倍型定义为，我们可以将这些基因型分为 4 个不同的 Tc I SL-IR 组，3 个对应于前单倍型 Ia（11 种基因型）、Ib（11 种基因型）和 Id（35 种基因型）；一个新的组，Ie（19 种基因型）。在我们的研究中未检测到携带 Tc Ic 基序的基因型。Tc Ia 与南美洲南部和北部的家庭循环以及中美洲和北美洲的森林循环有关。在来自哥伦比亚的所有传播循环中都发现了 Tc Ib。在来自阿根廷和哥伦比亚的所有传播循环中都鉴定出了 Tc Id，包括克氏心肌病患者、来自巴西的野生样本和来自法属圭亚那、巴拿马和委内瑞拉的人类病例。在阿根廷北部的 5 个家庭间三锥虫 infestans 样本、9 个野生 Mepraia spinolai 和 Mepraia gajardoi 样本和来自智利的 2 个克氏病患者和 1 个来自玻利维亚的克氏病再激活患者的样本中发现了 Tc Ie。在媒介粪便和来自人类和媒介样本的分离物中检测到了 Tc Ia+Tc Id、Tc Ia+Tc Ie 和 Tc Id+Tc Ie 的混合感染。此外，在一名心脏移植的克氏心肌病再激活患者的不同组织中发现了 Tc Ia 和 Tc Id，表明了组织嗜性。来自感染美国的 Triatoma gerstaeckeri 和 Didelphis virginiana、巴拉圭的 T. infestans、巴西的 Rhodnius nasutus 和 Rhodnius neglectus 以及智利的 M. spinolai 和 M. gajardoi 的 Tc I SL-IR 基因型是我们首次描述的。
