Molecular tests for malaria that can be performed with unprocessed samples

可以使用未处理的样本进行疟疾分子检测

• 批准号: 7904569
• 负责人: Huimin Kong
• 金额: $ 27.73万
• 依托单位: BIOHELIX CORPORATION
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7904569
• 关键词: Address; Anti-malarial drug resistance; Antimalarials; Biological Assay; Blood; Cause of Death; Chemistry; DNA; DNA amplification; Detection; Development; Diagnostic; Diagnostic tests; Gold; Immunoassay; Laboratories; Lateral; Malaria; Microscopy; Molecular; Nucleic Acids; Parasites; Patients; Performance; Pharmaceutical Preparations; Phase; Plasmodium; Plasmodium falciparum; Population; Relative (related person); Resistance; Resources; Rural; Sampling; Staging; Technology; Testing; Whole Blood; asexual; base; fighting; helicase; inhibitor/antagonist; internal control; manufacturing process; pathogen; public health relevance

DESCRIPTION (provided by applicant): This SBIR-AT-NIAID Phase I application addresses the problem of malaria diagnostics in resource- limited settings. BioHelix, has developed an isothermal nucleic acid amplification chemistry called helicase dependent amplification (HDA) that is tolerant of the DNA amplification inhibitors present in whole blood. This proposal will focus on the application of this technology to the detection of malarial asexual parasites without nucleic acid extraction. Based on our preliminary results, the expected sensitivity of the species-specific molecular test (~100 nucleic acid copies/5L blood) better than that possible with current rapid tests for asexual stages (200 copies of parasite/5L blood). Our specific objectives for this 2-year-long project are: 1. Develop an HDA assay to detect P. falciparum, P. vivax, P. ovale, and P. malariae. 2. Develop competitive internal controls (CIC) for the species-specific assay, as well as a 2-plex assay to detect the CIC with the targets in whole blood. 3. Develop manufacturing processes for the proposed assay kit that will enable field-use of the technology. 4. Evaluate the performance of the assay relative to the gold-standard tests. 5. Obtain CE marking for the assay. 6. Submit a pre-IDE to FDA as a preliminary step to seeking FDA clearance for the test. PUBLIC HEALTH RELEVANCE: As malaria is the leading cause death in endemic regions, the current treatment approach is not based on laboratory, or microscopy testing because establishing quality-assured microscopy in rural and resource- poor settings is difficult. The liberal use of anti-malarial drugs that results from such practices presents a problem in that resistance to first line drug treatments is wide-spread. This SBIR-AT-NIAID proposal focuses on the development of a species-specific for the detection of Plasmodium in blood. More sensitive, species- specific, and stage-specific diagnostic tests will help focus drug treatment, and may slow the spread of anti- malarial drug resistance in the pathogen population. Based on our preliminary results, the expected sensitivity of the species-specific DNA test (~100 nucleic acid copies/5L blood) will be better than that possible with current rapid tests for asexual stages (200 copies of parasite/5L blood). A more sensitive test that can be performed in the field near patients would greatly enhance malaria fighting activities. We anticipate tests in the range of $7-$10 for the HDA tests should be possible, if total test volumes reach 200,000.

描述(由申请人提供)：这项SBIR-AT-NIAID第一阶段申请解决了资源有限环境中的疟疾诊断问题。Biohelix公司开发了一种被称为解旋酶依赖扩增(HDA)的恒温核酸扩增化学，它对全血中存在的DNA扩增抑制剂具有耐受性。这项提案将侧重于将这项技术应用于不提取核酸的疟疾无性寄生虫的检测。根据我们的初步结果，物种特异性分子检测的预期灵敏度(~100个核酸拷贝/5L血液)好于目前无性阶段快速检测(200个寄生虫/5L血液)。我们在这个为期两年的项目中的具体目标是：1.建立一种检测恶性疟原虫、间日疟原虫、卵形疟原虫和疟疾的HDA方法。2.建立种属特异性检测的竞争性内对照(CIC)，以及检测全血中靶标的CIC的二重分析方法。3.为拟议的检测试剂盒制定制造工艺，使该技术能够在现场使用。4.相对于金标准测试，评估该检测的性能。5.获得化验的CE标记。6.向FDA提交一份IDE前测试报告，作为寻求FDA批准进行测试的初步步骤。 公共卫生相关性：由于疟疾是流行地区的主要死因，目前的治疗方法不是基于实验室或显微镜检测，因为在农村和资源贫乏的环境中建立质量有保证的显微镜是困难的。这种做法导致的抗疟疾药物的大量使用带来了一个问题，即对一线药物治疗的抵抗力普遍存在。这项SBIR-AT-NIAID建议的重点是开发一种特定物种的方法来检测血液中的疟原虫。更敏感、特定物种和特定阶段的诊断测试将有助于集中药物治疗，并可能减缓抗疟疾药物耐药性在病原体群体中的传播。根据我们的初步结果，物种特异性DNA检测的预期灵敏度(~100个核酸拷贝/5L血液)将好于目前无性阶段快速检测(200个寄生虫/5L血液)。可以在患者附近实地进行的更灵敏的测试将极大地加强疟疾防治活动。我们预计在7-10美元范围内的HDA测试测试应该是可能的，如果总测试量达到20万。