Oral transmission of Chagas disease: Typing of Trypanosoma cruzi from five outbreaks occurred in Venezuela shows multiclonal and common infections in patients, vectors and reservoirs
Oral transmission of Chagas disease: Typing of Trypanosoma cruzi from five outbreaks occurred in Venezuela shows multiclonal and common infections in patients, vectors and reservoirs
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DOI：
10.1016/j.meegid.2013.03.036
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发表时间：
2013-07-01
影响因子：
3.2
通讯作者：
Thomas, M. C.
中科院分区：
文献类型：
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作者：
Munoz-Calderon, A.;Diaz-Bello, Z.;Thomas, M. C.
委内瑞拉已描述了 6 起恰加斯病 (OChD) 经口传播事件，其中 2007 年报道的那一次共有 103 人感染，是全球规模最大的一次。这项工作展示了使用三种分子标记（微型外显子基因和核糖体 RNA 的 24S α 结构域和 18S 结构域）来表征感染克氏锥虫菌株的患者、宿主和媒介，这六起 OChD 疫情中有 5 起涉及其中。为此，通过 PCR 对 28 个克氏锥虫分离株进行了表征，并对这些反应的产物进行了克隆和测序，以揭示不同 TcI SL-IR 基因型的存在。我们还描述了一种新的 PCR 检测方法，能够区分 TcIb 和 TcId 寄生虫群体。总之，我们已经鉴定出大多数寄生虫具有 TcId 单倍型和以单倍型 TcId 为主的多克隆群体 (65.2%)。此外，单倍型 TcIb、TcIa 和混合物（TcId + TcIb、TcId + TcIa、TcIb + TcIa）群体在儿童样本中反复出现。 SL-IR 基序的分析显示两个克隆描绘了不同的基序，这可能是 TcIa 和 TcIb 之间可能存在混合单倍型（单倍型 TcIa/Ib）的证据。有趣的是，在一名患者中，发现治疗前和治疗后获得的克氏锥虫分离株之间存在单倍型差异。总之，我们的研究结果表明，为了了解口腔感染恰加斯病的致病机制，需要共同努力研究克氏锥虫单倍型、其组织向性及其对化学治疗的敏感性。 (c) 2013 Elsevier B.V. 保留所有权利。
In Venezuela six episodes of oral transmission of Chagas disease (OChD) have been described, being the one reported in 2007 with a total of 103 people infected the largest worldwide. This work shows the use of three molecular markers (mini-exon gene and domains 24S alpha and 18S of the ribosomal RNA) to characterize the infecting Trypanosoma cruzi strain of patients, reservoirs and vectors involved in five of the six OChD outbreaks. For this, 28 T. cruzi isolates were characterized by PCR, and the products of these reactions cloned and sequenced to reveal the existence of different TcI SL-IR genotypes. We also describe a new PCR assay able to discriminate between TcIb and TcId parasite populations. In summary, we have identified mostly parasites with the TcId haplotype and multiclonal populations with predominance of haplotype TcId (65.2%). Additionally, populations of haplotypes TcIb, TcIa and mixtures (TcId + TcIb, TcId + TcIa, TcIb + TcIa) are recurrent in samples obtained from children. The analysis of the SL-IR motif showed two clones depicting a different motif that could be an evidence for a possible hybrid haplotype between TcIa and TcIb (haplotype TcIa/Ib). Interestingly, in a single patient haplotype differences between T.cruzi isolates obtained pre and post-treatment were found. In conclusion, our findings show that in order to understand the pathogenic mechanisms involved in the orally adquired Chagas disease there is a need to join efforts to study T. cruzi haplotypes, their tissue tropisms and their susceptibility to chemoteaphy. (c) 2013 Elsevier B.V. All rights reserved.