Laboratório de Vigilância em Leishmanioses, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil.
J Trop Med. 2012;2012:808132. doi: 10.1155/2012/808132. Epub 2012 Dec 11.
The aim of this study was to investigate genetic polymorphism in Leishmania braziliensis population previously typed through isoenzyme electrophoresis, isolated from the same patient in two different moments: (A) before the beginning of treatment and (B) after treatment failure to meglumine antimoniate or reactivation after successful initial treatment. Fifteen pairs of isolates were assessed using the polymorphic molecular marker LSSP-PCR and following the phenetic analysis. The genetic profiles of the 30 samples were grouped in four clusters. Only two patients presented total identity in the A and B isolates. Most isolates presented similarity coefficients varying from 0.63 to 0.91. In this group of patients genetic polymorphisms could be observed indicating low similarity between the pairs of isolates. The results demonstrate the existence of genetic polymorphism between the samples isolated before treatment and after reactivation or treatment failure, suggesting a possible differentiation of the structure of the original parasite population which could be involved in the mechanisms of resistance to treatment or reactivation of lesions in the ATL. This phenomenon is important, although other factors also could be involved in this context and are discussed in this paper.
本研究的目的是调查先前通过同工酶电泳分型的巴西利什曼原虫种群的遗传多态性，这些寄生虫均来自同一位患者的两个不同时间点：（A）治疗开始前和（B）米替米星或两性霉素 B 治疗失败后复发。使用多态性分子标记 LSSP-PCR 对 15 对分离株进行评估，并进行表型分析。30 个样本的遗传谱分为 4 个群。只有两名患者的 A 期和 B 期分离株完全相同。大多数分离株的相似系数在 0.63 到 0.91 之间。在这群患者中观察到遗传多态性，表明治疗前和复发或治疗失败后分离的分离株之间存在低相似度。结果表明，治疗前和复发或治疗失败后分离的样本之间存在遗传多态性，这表明原始寄生虫种群的结构可能存在分化，这可能与治疗耐药或 ATL 病变复发的机制有关。虽然在这种情况下可能涉及其他因素，但这一现象很重要，本文对此进行了讨论。
