Molecular determinants of P. falciparum resistance to ACTs in Nigeria.

尼日利亚恶性疟原虫对 ACT 耐药性的分子决定因素。

• 批准号: 7292996
• 负责人: Christian T. Happi
• 金额: $ 2.79万
• 依托单位: COLLEGE OF MEDICINE, UNIVERSITY OF IBADAN
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-15 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7292996
• 关键词: ATP-Binding Cassette Transporters; Adoption; Africa; African; Age; Amodiaquine; Annual Reports; Anti-malarial drug resistance; Antimalarials; Appendix; Area; Artemisinins; Asians; Bioinformatics; Biological; Child; Chloroquine; Combined Modality Therapy; Country; Data; Detection; Development; Drug Combinations; Drug Design; Drug Formulations; Drug resistance; Drug usage; Enzyme-Linked Immunosorbent Assay; Epidemiologic Monitoring; Event; Falciparum Malaria; Future; Gene Frequency; Genes; Genetic; Genomics; Goals; Grant; Health; In Vitro; Infection; Infectious Disease Immunology; Knowledge; Laboratories; Laboratory Research; Malaria; Malaria Vaccines; Medical Surveillance; Medicine; Methodology; Methods; Modality; Molecular; Molecular Biology; Monitor; Morbidity - disease rate; Mutation; Nigeria; Only Child; Organism; Parasite resistance; Parasites; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Plasmodium; Plasmodium falciparum; Policies; Policy Maker; Polymerase Chain Reaction; Population; Predisposition; Preparation; Public Health; Publications; Pyrimethamine-Sulfadoxine; Quinine; Rate; Research; Research Activity; Research Infrastructure; Research Personnel; Research Project Grants; Resistance; Resistance development; Sampling; Schools; Shapes; South American; Structure; Techniques; Technology; Therapeutic Intervention; Training; Translating; United States National Institutes of Health; Universities; Variant; Work; artemether; artemisin; artemisinine; artesunate; base; benflumetol; chemotherapy; college; disorder prevention; drug discovery; experience; high throughput screening; in vivo; malarone; mortality; novel therapeutics; pressure; prevent; professor; programs; research study; response; success; tool; transmission process

DESCRIPTION (provided by applicant): The rapid development and spread of drug resistant Plasmodium falciparum is a serious global health problem and has contributed to increased mortality and morbidity caused by malaria. This situation has led to the adoption of artemisinin-based combination therapies (ACTs) for the management of malaria infections in many African countries including Nigeria. However, changes in antimalarial drug policies in many African countries were done without the availability of tools for large-scale monitoring of development and spread of P. falciparum resistance to the new drugs. In addition, there are concerns that parasites may soon become resistant to artemisin derivatives or partners drugs once they are introduced for management of malaria in Africa. Thus, researches leading to the definition of molecular determinants of parasites responses to artemisinin derivatives (ARTs) and partner drugs used in combination therapy are crucially needed, as they may unveil markers that are critical for efficient monitoring of drug resistant parasites as well as new chemotherapeutic targets. We hypothesized that combination of different mutations (SNPs) and/or differential expression in transporters and pfATPase6 genes of P. falciparum may be responsible for the differential in vitro or in vivo responses to artemisinin and partner drugs. Furthermore, multiple drug response determinants may be acting in different combinations resulting in differences between parasites phenotypes. This research is primarily directed at identifying and validating molecular determinants of resistance to artemisinin derivatives, lumefantrine (LUM) and amodiaquine (AQ) in fresh patients isolates of Plasmodium falciparum. Molecular determinants of parasites responses to antimalarials identified under this project will be used to develop a quick and simple high-throughput PCR-ELISA based tool/technique that detects SNPs in P. falciparum pfATPase6 and transporters genes as well as other parasites genes, for large- scale monitoring of parasites resistance to artemisinin derivatives and other antimalarials. To achieve these goals the following specific activities will be carried out over a 3 year period: 1) Evaluate the efficacy and in vitro susceptibility of P. falciparum to artemether-lumefantrine and artesunate- amodiaquine combinations in Southwest Nigeria; 2) determine parasites population diversity and assess the presence of SNPs in genes (selected transporters or pfATPase6) in fresh isolates of P. falciparum obtained from patients; 3) evaluate and compare SNPs patterns in selected P. falciparum transporters and pfATPase6 genes in patients isolates and freshly cloned parasites before and following drug (AQ, LUM and ARTs) pressure; 4)Collate SNPs patterns of transporters genes and pfATPase6 with in vitro susceptibility profile, treatment modalities in order to Identify molecular determinants of ARTs, LUM or AQ, and the development of unique resistant phenotypes; 5) use molecular determinants (SNPs) of P. falciparum response to ARTs, LUM or AQ to develop a simple high- throughput method for large-scale monitoring/surveillance of drug resistant parasites to artemisinin and partner drugs used in combination therapy for malaria in Nigeria. This research project provides a unique opportunity to use Research Infrastructures and Capacities developed in Nigeria under the FIRCA Grant no. NIH RO3TW006298, for a better understanding of the development and spread of resistance to ACTs and other antimalarial drugs. Data obtained and tools developed by this project will be made available to the Nigerian National Malaria Control Program in order to promote evidence-based antimalarial drugs policy in the country. . This research project has a direct relevance to the problem of drug resistance in Nigeria and Africa. It provides a unique opportunity to use Research Infrastructures, Capacities Developed in Nigeria under the FIRCA Grant no. NIH RO3TW006298 as well as the technologies to be developped under the current project to better understand the development and spread of parasites resistance to ACTs and other antimalarial drugs. Data obtained and tools developed by this project will be made available to the Nigerian National Malaria Control Program in order to promote evidence-based antimalarial drugs policy.

描述（由申请人提供）：耐药性恶性疟原虫的快速发展和传播是一个严重的全球健康问题，并导致疟疾引起的死亡率和发病率增加。这种情况导致包括尼日利亚在内的许多非洲国家采用基于青蒿素的联合疗法（ACT）来治疗疟疾感染。然而，许多非洲国家抗疟药物政策的改变是在没有大规模监测恶性疟原虫对新药耐药性发展和传播的工具的情况下进行的。此外，人们担心，一旦将青蒿素衍生物或伙伴药物引入非洲治疗疟疾，寄生虫可能很快就会对其产生抗药性。因此，迫切需要进行研究来定义寄生虫对青蒿素衍生物（ART）和联合治疗中使用的伙伴药物反应的分子决定因素，因为它们可能揭示对于有效监测耐药寄生虫以及新的化疗药物至关重要的标记物目标。我们假设恶性疟原虫转运蛋白和 pfATPase6 基因中不同突变 (SNP) 和/或差异表达的组合可能是青蒿素及其伙伴药物的体外或体内反应差异的原因。此外，多种药物反应决定因素可能以不同的组合作用，导致寄生虫表型之间的差异。这项研究主要旨在识别和验证恶性疟原虫新分离株对青蒿素衍生物、本芴醇 (LUM) 和阿莫地喹 (AQ) 耐药的分子决定因素。该项目下确定的寄生虫对抗疟药反应的分子决定因素将用于开发一种快速、简单的基于高通量 PCR-ELISA 的工具/技术，用于检测恶性疟原虫 pfATPase6 中的 SNP 和转运蛋白基因以及其他寄生虫基因，以检测大量疟原虫。 - 大规模监测寄生虫对青蒿素衍生物和其他抗疟药的耐药性。为了实现这些目标，将在三年内开展以下具体活动： 1) 评估尼日利亚西南部恶性疟原虫对蒿甲醚-本芴醇和青蒿琥酯-阿莫地喹组合的功效和体外敏感性； 2) 确定从患者获得的新鲜恶性疟原虫分离株中的寄生虫种群多样性并评估基因（选定的转运蛋白或 pfATPase6）中 SNP 的存在； 3) 评估和比较药物（AQ、LUM 和 ART）压力前后患者分离株和新克隆寄生虫中选定的恶性疟原虫转运蛋白和 pfATPase6 基因的 SNP 模式； 4) 将转运蛋白基因和 pfATPase6 的 SNP 模式与体外敏感性概况、治疗方式进行比较，以确定 ART、LUM 或 AQ 的分子决定因素，以及独特耐药表型的发展； 5) 利用恶性疟原虫对 ART、LUM 或 AQ 反应的分子决定簇 (SNP) 开发一种简单的高通量方法，用于大规模监测/监测青蒿素和用于疟疾联合治疗的伙伴药物的耐药寄生虫尼日利亚。该研究项目提供了一个独特的机会，可以利用尼日利亚根据 FIRCA 拨款号开发的研究基础设施和能力。 NIH RO3TW006298，用于更好地了解 ACT 和其他抗疟药物耐药性的发展和传播。该项目获得的数据和开发的工具将提供给尼日利亚国家疟疾控制计划，以促进该国循证抗疟药物政策。 。该研究项目与尼日利亚和非洲的耐药性问题直接相关。它提供了一个独特的机会，可以利用尼日利亚根据 FIRCA 拨款号开发的研究基础设施和能力。 NIH RO3TW006298 以及当前项目下要开发的技术，以更好地了解寄生虫对 ACT 和其他抗疟药物耐药性的发展和传播。该项目获得的数据和开发的工具将提供给尼日利亚国家疟疾控制计划，以促进循证抗疟药物政策。