Pathogenesis and Diagnosis

项目总结（见说明）：恶性疟原虫所表现出的丰富的遗传多样性，是由宿主和媒介免疫力、药物压力、环境变化形成的？是它成功成为持久性病原体的关键因素了解遗传多样性的性质、范围和分布以及它如何随时间变化，将是制定最有效和最有效率的疟疾控制措施的关键。迄今为止，没有关于非洲南部地区恶性疟原虫群体遗传学的数据。研究区C的总体目标是建立ICEMR研究地点恶性疟原虫群体遗传学的区域概况。这将通过使用基于阵列和基于PCR的方法来实现，这些方法将提供寄生虫遗传多样性的高分辨率和低分辨率概况。除了基于人群的问题外，已证实的裂殖子表面蛋白-2（msp 2）基因分型检测将用于评估个体内寄生虫多样性，特别强调低传播地区的无症状/沉默感染。目的1）获得ICEMR研究点内和研究点之间寄生虫分离株基因型差异的高分辨率图谱，以确定寄生虫遗传多样性的性质和范围。这些研究将使用Affyandroid平台上的高密度恶性疟原虫平铺阵列。目的2）实施和完善基于PCR的条形码方法，作为一种简单，具有成本效益的工具，用于常规监测ICEMR研究地点寄生虫种群遗传结构的变化。条形码将由通过真实的时间RT PCR定义的~ 25个SNP组成。虽然条形码将提供比基于阵列的方法更低分辨率的基因型，但其较低的成本和易用性将允许更全面地了解区域种群遗传结构，这将有助于识别由于控制措施或其他因素而随时间发生的变化。目的3）确定在ICEMR研究地点的低和高传播地区居住的个体内寄生虫克隆多样性的水平和动态。将根据PCR检测msp 2基因多态性评估感染复数（MOI）。将特别强调无症状和隐性感染以及这些人在传播中可能发挥的作用。预期基因分型和MOI数据将用于建立预测遗传多样性对传播动力学、药物治疗效果和发病机制影响的模型

PROJECT SUMMARY (See instructions): The abundant genetic diversity exhibited by P. falciparum, shaped by host and vector immunity, drug pressure, environmental change? is a key element to its success as a persistent pathogen. Understanding the nature, extent and distribution of genetic diversity and how it changes over time will be key to devising the most efficient and effective control measures for malaria. To date, there is no data on the population genetics of P. falciparium in the southern region of Africa. The overall goal of Research Area C is to establish regional profiles of the population genetics of P. falciparium in the ICEMR study sites. This will be accomplished using array-based and PCR-based approaches that will provide both high- and low-resolution profiles of parasite genetic diversity. In addition to population-based issues, the proven merozoite surface protein-2 (msp2) genotyping assay will be used to assess intra-individual parasite diversity with special emphasis in asymptomatic/silent infection in areas of low transmission. Aim 1) Obtain a high-resolution profile ofthe genotypic differences between parasite isolates within and between ICEMR study sites in order to establish the nature and scope of parasite genetic diversity. A high-density P. falciparum tiling array on the Affymetrix platform will be used for these studies. Aim 2) Implement and refine a PCR-based barcode approach as a simple, cost-effective tool for routinely monitoring changes in the genetic structure of parasite populations in the ICEMR study sites. The barcode will consist of -25 SNPs defined by real time RT PCR. While the barcode will provide a lower resolution genotype than the array-based approach, its lower cost and ease of use will allow a much more comprehensive profile of regional population genetic structure that will facilitate the identification of changes over time due to control measures or other factors. Aim 3) Determine the level and dynamics of parasite clonal diversity within individuals residing in low- and high-transmission areas in the ICEMR study sites. Multiplicity of infection (MOI) will be assessed based on the detection of polymorphisms in the msp2 gene by PCR. Special emphasis will be placed on asymptomatic and silent infections and the role that these individuals may have in transmission. The expectatoin is that the genotyping and MOI data will be used to create models for prediction of genetic diversity influence upon transmission dynamics, drug treatment efforts, and pathogenesis