Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA.
Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA.
复制标题
来自美国加利福尼亚州的载体triatoma protracta中检测到的锥虫的分子多样性。
DOI：
10.1371/journal.pntd.0004291
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发表时间：
2016-01
影响因子：
3.8
通讯作者：
Mazet JA
中科院分区：
文献类型：
--
作者：
Shender LA;Lewis MD;Rejmanek D;Mazet JA
克氏锥虫是人类和狗恰加斯病的病原体，是一种媒介传播的人畜共患原生动物寄生虫，可导致致命的心脏病。虽然美洲锥虫病被认为是拉丁美洲经济上最重要的寄生虫感染，但在美利坚合众国，美洲锥虫病的发病率可能被低估，甚至还在增加。T. cruzi在拉丁美洲是有据可查的，并且可能影响疾病进展、严重程度和治疗效果;然而，关于T.美国特有的克氏病毒株因此，重要的是扩大我们的知识，美国T。cruzi菌株，以改善对局部获得性感染的识别和应答。我们对T. cruzi的分子多样性，增加了南加州的稀疏遗传数据，并首次调查了北方加州的遗传序列。从加州南部（埃斯孔迪多和洛杉矶）和北方（瓦列西托）地区采集了媒介长锥蝽。通过敏感的核重复DNA和动基体小环DNA PCR检测对样本进行初步筛选，得出加州南部和北方地区的总体患病率分别约为28%和55%。阳性样本进一步处理，以确定离散分型单位（DTU），揭示TcI和TcIV谱系在南加州，但只有TcI在北方加州。对一部分阳性样本进行系统发育分析（靶向COII-ND 1、TR和RB 19基因），以比较加利福尼亚T. cruzi样本与来自美国其他地区和拉丁美洲的菌株进行比较。结果表明，在TcI DTU中，加州的序列与来自美国东南部的序列相似，也与来自拉丁美洲的几个导致人类恰加斯病的分离株相似。加州的长鼻锥口线虫种群经常感染T.克鲁兹我们的数据扩展了TcI的范围的北方界限，并确定了一个新的TcI和TcIV之间的遗传交换事件。来自加州和特定拉丁美洲菌株的序列之间的高度相似性表明美国菌株可能同样能够引起人类疾病。加利福尼亚和其他美国T.推荐使用Cruzi菌株。克氏锥虫（Trypanosoma cruzi）是一种原生动物寄生虫，可引起人类和狗的恰加斯病，并可能最终导致与心力衰竭相关的死亡。这种寄生虫最常通过锥蝽媒介传播，通常称为“接吻虫”。虽然南美锥虫病主要是在拉丁美洲国家获得，T。克鲁兹存在于美国（US）某些地区（包括加州地区）的野生动物和病媒中。在美国，偶尔有当地获得性恰加斯病的病例报告，最近的血清学调查表明，T。克鲁斯暴露可能比以前认识到的更普遍地发生。然而，相对较少的分子研究已经进行了T。在美国，特别是在加州，存在克氏菌株。在这项研究中，我们从北方和加州南部收集了近100只接吻虫，以确定T。每个地区的接吻虫种群的克鲁兹流行率和遗传多样性。我们将本研究中获得的DNA序列与几个T.在拉丁美洲和美国东南部发现的克鲁齐菌株。根据我们的数据，我们得出结论，加州T。克鲁齐病毒样本与拉丁美洲发现的已知与人类感染有关的菌株密切相关。
Trypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US) may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections. We conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles) and northern (Vallecito) California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs), revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes) were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans. Triatoma protracta populations in California are frequently infected with T. cruzi. Our data extend the northern limits of the range of TcI and identify a novel genetic exchange event between TcI and TcIV. High similarity between sequences from California and specific Latin American strains indicates US strains may be equally capable of causing human disease. Additional genetic characterization of Californian and other US T. cruzi strains is recommended. Trypanosoma cruzi is a protozoan parasite that causes Chagas disease in humans and dogs and may eventually lead to mortalities related to cardiac failure. This parasite is most frequently transmitted by triatomine bug vectors, commonly called “kissing bugs.” Although Chagas disease is predominately acquired in Latin American countries, T. cruzi exists in wildlife and vectors in some parts of the United States of America (US), including regions of California. Within the US, occasional cases of locally acquired Chagas disease have been reported, and recent serological surveys indicate that T. cruzi exposure may be occurring more commonly than previously realized. However, relatively little molecular research has been performed on the T. cruzi strains present in the US, especially within California. In this study, we collected nearly 100 kissing bugs from regions of northern and southern California to determine the T. cruzi prevalence and genetic diversity for each region’s kissing bug population. We compared DNA sequences obtained in this study to those of several T. cruzi strains found in Latin America and the southeastern US. Based on our data, we conclude that Californian T. cruzi samples are closely related to strains found in Latin America known to be associated with human infections.