Strep-CaDI: A fast, accurate, and sensitive point-of-care test for Group A Streptococcus

Strep-CaDI：快速、准确且灵敏的 A 组链球菌现场检测

• 批准号: 10699852
• 负责人: Zachary David Call
• 金额: $ 27.96万
• 依托单位: BURST DIAGNOSTICS LLC
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10699852
• 关键词: 2019-nCoV; 3D Print; Antibiotic Therapy; Antibiotics; Antibodies; Antigens; Antimicrobial Resistance; Bacteria; Biological Assay; Blood capillaries; Buffers; COVID-19 outbreak; Child; Clinic; Clinical; Colorado; Communicable Diseases; Detection; Development; Device Designs; Devices; Diagnostic; Diagnostic Procedure; Disease; Dose; Enzyme-Linked Immunosorbent Assay; Evaluation; Exposure to; Feedback; Film; Funding; Future; Generations; Goals; Health Personnel; Home; Housing; Human Resources; Immunoassay; Individual; Infection; Infrastructure; Injections; Kinetics; Label; Laboratories; Legal patent; Manuals; Marketing; Methods; Microfluidic Microchips; Microfluidics; Modeling; Molds; Molecular; Outcome; Paper; Patient Care; Patients; Penetration; Performance; Pharyngeal structure; Pharyngitis; Physicians; Polyesters; Procedures; Protocols documentation; Pump; RADx; Rapid diagnostics; Reaction; Reading; Reagent; Reporting; Running; SARS-CoV-2 antigen; Sampling; Sensitivity and Specificity; Series; Signal Transduction; Sore Throat; Speed; Streptococcus pyogenes; Swab; Symptoms; System; Technology; Telemedicine; Test Result; Testing; Time; Training; Treatment Protocols; United States National Institutes of Health; Universities; Work; accurate diagnosis; acute symptom; antigen detection; cost; design; detection limit; detection test; gut microbiome; home test; hydrophilicity; improved; instrumentation; manufacture; nanoparticle; operation; phase 2 study; physical symptom; point of care; point of care testing; point-of-care diagnostics; preservation; prototype; rapid test; rural health clinic; screening; stem

SUMMARY The current rapid antigen detection tests for group A strep lack sensitivity and result in upwards of 10 million unnecessary antibiotic treatments provided to children each year. Current diagnostic methods utilized when a patient presents at a clinic with a sore throat include a throat swab and rapid strep test. A positive rapid test results in antibiotic prescription, but due to the low sensitivity of existing rapid strep immunoassays, physicians often prescribe antibiotics as a precaution while waiting for culture results after a negative rapid test. It is estimated that up to 70% of these doses are unnecessary, contributing to the rise in antimicrobial resistance. While ELISAs and molecular (PCR-based) assays with improved sensitivity have been reported to reduce unnecessary antibiotic treatment, these tests rely on laboratory instrumentation and significant infrastructure, making them unsuitable for point-of-care settings and rural clinics, and impossible to implement as at-home testing protocols for telemedicine purposes. Thus, there is an urgent unmet need for an improved, ultrasensitive rapid strep test that could reduce the unnecessary use of antibiotics, stemming the increase in antimicrobial resistance and preserving the gut microbiome of children. Furthermore, if an improved rapid strep test could be optimized for robustness and ease of use, as well as sensitivity, it could be performed at home enabling telemedicine protocols and reducing the need for a potentially infected individual to expose frontline healthcare workers. The outcome of this project will be a proof-of- principle demonstration of an ultrasensitive rapid strep test with onboard reagents that requires a simple swab insertion step to initiate to completion with limits of detection 10-100x lower than current dipstick methods. Improved sensitivity will be achieved through use of the Capillary-Driven Immunoassay (CaDI) technology in which we are able to integrate all steps of highly sensitive, laboratory-performed ELISAs (washing, labeling, and amplification) on a simple microfluidic device without requiring instrumentation or highly trained personnel. This first-in-its-class microfluidic point-of-care (POC) device will be realized through the following aims. First, proof of concept for a Strep-CaDI rapid strep test will be demonstrated for the ultrasensitive detection of Streptococcus pyogenes antigen in spiked buffer through antibody screening and assay parameter optimization. Secondly, the bacterial extraction method and corresponding CaDI parameters and device design will be optimized for use with clinical samples spiked with whole bacteria. The final, optimized design will be compared to current market solutions to compare assay sensitivity (LOD), time to result, and complexity (steps to result). Lastly, to increase the likelihood of approval for at-home use and to provide a clear market advantage over current solutions, we will prototype (through modeling, 3D printing, and testing) an assay housing capable of simplifying CaDI operation to a simple swab->insert-> read mechanism which initiates the assay to completion and isolates all reagents from the operator. Once the required functionality is achieved, the housing and immunoassay will be tested by untrained individuals. Feedback from these trials will be used for housing design iterations. Completion of these three aims will result in a prototype rapid strep test with the ease-of-use of a simple dipstick test and the sensitivity of a laboratory ELISA.

概括 A组的当前快速抗原检测测试缺乏灵敏度，导致不必要的超过1000万 每年提供给儿童的抗生素治疗。当患者在诊所出现时使用的当前诊断方法 喉咙痛包括喉咙拭子和快速链球菌测试。阳性快速测试导致抗生素处方，但应有 对于现有快速链球菌免疫测定的低灵敏度，医生通常会开出抗生素作为预防措施 在快速测试下等待培养结果。据估计，这些剂量中最多有70％是不必要的 有助于抗菌素耐药性的升高。而ELISA和分子（基于PCR）的测定法 据报道，敏感性降低了不必要的抗生素治疗，这些测试依赖于实验室仪器和 重要的基础设施，使其不适合护理点环境和乡村诊所，并且无法实施 作为用于远程医疗目的的家庭测试方案。因此，紧急无法满足的超敏感 可以减少不必要使用抗生素的快速链球菌测试，从而促进抗菌耐药性和 保留儿童的肠道微生物组。此外，如果可以优化改进的快速链球菌测试，以实现鲁棒性 易用性以及敏感性，可以在家中执行以实现远程医疗协议并减少需求 对于潜在感染的人，可以揭露一线医疗保健工作者。该项目的结果将是 超敏感快速测试的原理演示，其板载试剂需要简单的拭子插入步骤 启动以比当前量强壮方法低10-100倍的检测限制完成。提高灵敏度将是 通过使用毛细管驱动的免疫测定（CADI）技术实现，我们能够整合所有步骤 简单的微流体设备上的高度敏感，实验室绩效的ELISA（洗涤，标签和放大） 不需要仪器或训练有素的人员。这是一流的微流体护理（POC）设备 将通过以下目标实现。首先，将展示链球菌-CADI快速链球菌测试的概念验证证明 通过抗体筛选和测定 参数优化。其次，细菌提取方法和相应的CADI参数和设备设计 将被优化，以供与全细菌尖刺的临床样品一起使用。最终优化的设计将与 当前的市场解决方案比较测定敏感性（LOD），结果的时间和复杂性（结果步骤）。最后，要 增加批准在家使用的可能性，并为当前解决方案提供明显的市场优势，我们将 原型（通过建模，3D打印和测试）能够简化CADI操作的测定外壳 Swab->插入 - >读取机制，该机制启动完成测定，并将所有试剂与操作员分离。一次 达到所需的功能，住房和免疫测定法将由未经训练的个体进行测试。来自 这些试验将用于住房设计迭代。这三个目标的完成将导致原型快速链球菌 用简单的尺寸测试的易用性和实验室ELISA的灵敏度进行测试。