A Binary Probe-Based DNAzyme Cascade for Rapid Detection of MRSA/MSSA

该STTR一期项目将开发一种概念验证的分子检测方法，用于快速检测金黄色葡萄球菌（SA），并在没有PCR扩增的情况下区分耐甲氧西林SA （MRSA）和耐甲氧西林SA （MSSA）。双DNAzyme探针将被设计成与mrsa特异性基因或sa特异性基因互补。在目标基因存在的情况下，二元探针将组装成具有催化活性的DNAzyme并激活DNAzyme级联，提供视觉或比色读出。第一阶段的研究将集中于设计双DNAzyme探针，构建DNAzyme级联，并展示MRSA/MSSA筛选的技术可行性。与MSSA感染相比，MRSA感染的治疗选择有限，并导致明显更高的发病率、死亡率和医疗费用。因此，快速可靠地检测SA并区分MRSA和MSSA将具有重大的临床、经济和社会影响。如果开发成功，提议的DNAzyme级联方法将显著提高当前无pcr分子测试的检测极限，并有可能发展成为商业上可行的、独立的单管分析，只需最少的动手时间，不需要复杂的仪器。

DESCRIPTION (provided by applicant): A binary probe-based DNAzyme cascade for rapid detection of MRSA/MSSA Project Summary This STTR Phase I project will develop a proof-of-concept molecular test for rapid detection of Staphylococcus aureus (SA) and differentiation between methicillin-resistant SA (MRSA) and methicillin-susceptible SA (MSSA) in the absence of PCR amplification. Binary DNAzyme probes will be designed to be complementary to an MRSA-specific gene or to an SA-specific gene. In presence of a target gene, the binary probes will be assembled into a catalytically active DNAzyme and activate a DNAzyme cascade, providing a visual or colorimetric readout. The Phase I research will focus on designing the binary DNAzyme probes, constructing the DNAzyme cascade, and demonstrating the technical feasibility for MRSA/MSSA screening. Compared to MSSA infections, MRSA infections have limited treatment options and result in significantly higher morbidity, mortality, and healthcare costs. Therefore, rapid and reliable detection of SA and differentiation between MRSA and MSSA will have significant clinical, economic, and societal impacts. If successfully developed, the proposed DNAzyme cascade approach will significantly improve the detection limit of current PCR-free molecular tests and have the potential to be developed into commercially viable, self-contained single-tube assays with minimum hands-on time and no requirement for sophisticated instrument. PUBLIC HEALTH RELEVANCE: Staphylococcus aureus, particularly MRSA, is a major cause of infections ranging from skin and soft tissue infections to invasive, life-threatening infections such as bacteremia, endocarditis, etc. The proposed PCR-free molecular test would address an urgent and unmet need for rapid, sensitive, and specific screening of MRSA and MSSA in an easy-to-use, cost- effective way, thereby allowing for timely and accurately treatment of MRSA/MSSA infections and helping reduce the associated healthcare costs.