Venegas Juan, Díaz Felipe, Rojas Tamara, Miranda Sandra, Jercic M I, González Christian, Coñoepán William, Vargas Alex, Pichuantes Sergio, Gajardo Marta, Rodríguez Jorge, Sánchez Gittith
Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, correo, 70086, Santiago 7, Chile.
Acta Parasitol. 2013 Jun;58(2):139-48. doi: 10.2478/s11686-013-0123-0. Epub 2013 May 11.
The objective of this study was to investigate if there is specific host-parasite association in Chilean populations of Trypanosoma cruzi. For this purpose, two groups of parasites were analyzed, one from chronic chagasic patients, and the other from Triatoma infestans triatomines in three regions of the country. The first group consisted of four types of samples: parasites from peripheral blood of non-cardiopathic T. cruzi infected patients (NB); parasites from their corresponding xenodiagnosis (NX); parasites from peripheral blood of T. cruzi infected cardiopathic patients (CB) and parasites from their xenodiagnostics (CX). The T. infestans sample in turn was from three regions: III, V and M (Metropolitan). The genetic differentiation by the Fisher exact method, the lineage distribution of the samples, the molecular phylogeny and the frequency of multiclonality were analysed. The results show that not only are the groups of T. cruzi clones from Chagas disease patients and vectors genetically differentiated, but also all the sub-groups (NB, NX, CB and CX) from the III, V and M regions. The analysis of lineage distribution was concordant with the above results, because significant differences among the percentages of TcI, TcIII and hybrids (TcV or TcVI) were observed. The phylogenetic reconstruction with these Chilean T. cruzi samples was coherent with the above results because the four chagasic samples clustered together in a node with high bootstrap support, whereas the three triatomine samples (III, V and M) were located apart from that node. The topology of the tree including published T. cruzi clones and isolates was concordant with the known topology, which confirmed that the results presented here are correct and are not biased by experimental error. Taken together the results presented here are concordant with a specific host-parasite association between some Chilean T. cruzi populations.
本研究的目的是调查在智利克氏锥虫种群中是否存在特定的宿主 - 寄生虫关联。为此，分析了两组寄生虫，一组来自慢性恰加斯病患者，另一组来自该国三个地区的感染锥蝽。第一组由四种类型的样本组成：来自未患心脏病的克氏锥虫感染患者外周血的寄生虫（NB）；来自其相应 xenodiagnosis 的寄生虫（NX）；来自克氏锥虫感染心脏病患者外周血的寄生虫（CB）以及来自其 xenodiagnostics 的寄生虫（CX）。锥蝽样本依次来自三个地区：第三区、第五区和大都会区（M）。采用 Fisher 精确法分析了遗传分化、样本的谱系分布、分子系统发育以及多克隆性频率。结果表明，不仅来自恰加斯病患者和病媒的克氏锥虫克隆群体在遗传上有差异，而且来自第三区、第五区和大都会区的所有亚组（NB、NX、CB 和 CX）也存在差异。谱系分布分析与上述结果一致，因为观察到 TcI、TcIII 和杂交种（TcV 或 TcVI）的百分比之间存在显著差异。用这些智利克氏锥虫样本进行的系统发育重建与上述结果一致，因为四个恰加斯病样本在一个具有高自展支持的节点上聚集在一起，而三个锥蝽样本（第三区、第五区和大都会区）则位于该节点之外。包含已发表的克氏锥虫克隆和分离株的树的拓扑结构与已知拓扑结构一致，这证实了此处呈现的结果是正确的，且不受实验误差的影响。综上所述，此处呈现的结果与智利一些克氏锥虫种群之间特定的宿主 - 寄生虫关联一致。
