Laboratório de Malária, Instituto de Pesquisa René Rachou-Fiocruz, Av. Augusto de Lima 1715, 30190-002 Belo Horizonte, MG, Brasil.
Mem Inst Oswaldo Cruz. 2011 Aug;106 Suppl 1:27-33. doi: 10.1590/s0074-02762011000900004.
Reliable molecular markers are essential for a better understanding of the molecular epidemiology of Plasmodium vivax, which is a neglected human malaria parasite. The aim of this study was to analyze the genetic diversity of P. vivax isolates from the Brazilian Amazon using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the highly polymorphic merozoite surface protein-3alpha (PvMSP-3α) gene. To accomplish this, 60 isolates of P. vivax from different endemic areas in the Brazilian Amazon were collected. The PvMSP-3α gene was amplified by nested-PCR. Three major types of the PvMSP-3α locus were detected at different frequencies: type A (68%), B (15%) and C (17%). A single sample showed two PCR fragments, which corresponded to infection with types A and C. PCR-RFLP analysis using the HhaI restriction enzyme for 52 isolates clearly identified 11 haplotypes, eight of which were from type A, two from type B and only one from type C. Seven other isolates did not show a clear pattern using PCR-RFLP. This result might be due to multiple clone infections. This study showed a high diversity of the PvMSP-3α gene among P. vivax isolates from the Brazilian Amazon, but also indicated that the detection performance of PCR-RFLP of the PvMSP-3α gene may not be sufficient to detect multiple clone infections.
可靠的分子标记对于更好地了解被忽视的人类疟原虫——间日疟原虫的分子流行病学至关重要。本研究旨在通过聚合酶链反应-限制性片段长度多态性（PCR-RFLP）分析高度多态的裂殖子表面蛋白-3α（PvMSP-3α）基因，分析来自巴西亚马逊地区的间日疟原虫分离株的遗传多样性。为此，收集了来自巴西亚马逊地区不同流行地区的 60 株间日疟原虫分离株。通过巢式 PCR 扩增 PvMSP-3α 基因。在不同频率下检测到 PvMSP-3α 基因座的三种主要类型：A 型（68%）、B 型（15%）和 C 型（17%）。一个样本显示两个 PCR 片段，分别对应 A 型和 C 型感染。对 52 株进行的 HhaI 限制酶 PCR-RFLP 分析清楚地鉴定出 11 种单倍型，其中 8 种来自 A 型，2 种来自 B 型，仅 1 种来自 C 型。其他 7 个分离株未显示明显的 PCR-RFLP 模式。这一结果可能是由于多克隆感染所致。本研究表明，来自巴西亚马逊地区的间日疟原虫分离株的 PvMSP-3α 基因具有高度多样性，但也表明 PvMSP-3α 基因的 PCR-RFLP 检测性能可能不足以检测多克隆感染。
