Determinants of Drug Resistant Malaria in Nigeria

描述(由申请人提供) 恶性疟原虫对氯喹的抗性机制尚不清楚，仍存在较大争议。恶性疟原虫pfmdrl和pfcrt基因突变与氯喹耐药性有关。然而，这两个基因的突变与体外或体内氯喹耐药性之间没有绝对的相关性。这一事实暗示了寄生虫中氯喹抗性的其他决定因素的潜在参与。这项研究主要是为了研究pfmdrl、pfcrt和其他决定因素在恶性疟原虫尼日利亚分离株氯喹抗性中的作用。我们还建议使用氯喹和磺胺多辛-乙胺耐药性的分子标记作为监测工具，监测这些药物在尼日利亚随着时间的推移疗效的变化。这项研究工作产生的数据将提供给国家疟疾控制方案，以促进尼日利亚疟疾治疗的循证政策。为实现这些目标，将在三年内开展下列活动。 1.确定接受氯喹治疗的恶性疟原虫分离株对氯喹敏感性的遗传相关性。恶性疟原虫氯喹抗性决定基因(I)pfcrt和(Ii)pfmdrl基因突变的存在将通过DNA测序分析来确定。 2.验证氯喹抗性决定簇在恶性疟原虫患者分离株克隆中的作用。 3.确定恶性疟原虫磺胺多辛-乙胺嘧啶耐药相关基因DHFR和DHPS的背景突变发生率。 4.在尼日利亚建立一个地点，作为国家参考实验室，研究耐药恶性疟原虫在尼日利亚随时间的发展和传播情况。 这一研究项目提供了一个独特的机会，可以将尼日利亚的研究地点作为一线，以研究和更好地了解该国耐药性的发展和传播。这项研究将主要在伊巴丹进行，在伊巴丹大学医学院疟疾研究实验室与Christian Happi博士合作，作为NIH赠款的延伸，5 R01 GM61351-04；05/01/2000-04/30/2004。

DESCRIPTION (provided by applicant) The mechanism of chloroquine resistance in Plasmodium falciparum is not clearly understood and remains very controversial. Mutations in Plasmodium falciparum pfmdrl and pfcrt genes have been associated with chloroquine resistance. However, there is no absolute correlation between mutations in each of these two genes and in vitro or in vivo chloroquine resistance. This fact implies the potential involvement of other determinants of chloroquine resistance in the parasite. This research is primarily directed at investigating the role of pfmdrl, pfcrt and additional determinants of chloroquine resistance in P. falciparum in Nigerian isolates. We also propose to use molecular markers of chloroquine and sulfadoxine-pyrimethamine resistance as a surveillance tool for monitoring changes in the efficacy of these drugs over time in Nigeria. Data generated by this research work will be made available to the national malaria control program in order to promote evidence-based policy on malaria therapy in Nigeria. To achieve these goals, the following activities will be carried out over a 3-year period. 1. Determine genetic correlates of chloroquine sensitivity in P. falciparum isolates from patients treated with chloroquine. The presence of mutations in P. falciparum chloroquine resistance determinant genes (i) pfcrt, and (ii) pfmdrl genes will be determined by DNA sequencing analysis. 2. Validate the role of chloroquine resistance determinants in P. falciparum clones prepared from patients' isolates. 3. Determine the background mutation prevalence in the DHFR and DHPS genes associated with P. falciparum sulfadoxine-pyrimethamine resistance in Nigerian isolates. 4.Establish a site in Nigeria that will serve as the national reference laboratory to study the development and spread of drug resistant Plasmodium falciparum over time in Nigeria. This research project provides a unique opportunity to use the study site in Nigeria as a front-line, in order to study and better understand the development and spread of drug resistance in the country. The research will be done primarily in Ibadan, at the Malaria Research laboratory, PIMRAT, University of Ibadan's College of Medicine in Collaboration with Dr. Christian Happi as an extension of the NIH grant 5 R01 GM61351-04; 05/01/2000-04/30/2004.