Rapid sensitive low cost test for resistant microbes causing hospital infections

描述（由申请人提供）：我们建议开发一种新型检测平台，以快速、超灵敏、准确、用户友好和具有成本效益的方式筛查经常导致严重医院获得性感染的抗生素耐药细菌。每年有近10万人死于200万例严重的医院获得性感染，估计费用为305亿美元。其中约有20，000例死亡是由耐甲氧西林金黄色葡萄球菌（MRSA）引起的。在过去的30年里，医院获得性感染的比率和MRSA的传播都急剧增加。许多人现在携带MRSA在他们的身体，即使是健康的。当MRSA携带者住院时，耐药微生物可能会导致携带者和医院其他人严重感染。最近的研究表明，医院可以通过对住院患者进行MRSA筛查，然后使用严格的感染控制程序（包括隔离）对其进行治疗，从而大大减少医院获得性感染的发生。传统的微生物方法筛选MRSA的患者是非常缓慢的，需要几天，因此是不兼容的快速识别和分离的MRSA携带者。基于核酸扩增的新的快速MRSA测试在一些站点用于MRSA筛查。然而，这些测试是昂贵的，复杂的，因此目前在大多数医院的大规模筛查是不实用的。我们的目标是开发一种新的快速，灵敏，易于使用的系统，大规模的成本效益的MRSA筛查。该系统的专有技术使用低成本的非放大数字成像来计数单个S。用高荧光颗粒特异性标记的金黄色葡萄球菌细胞。该测试确定S的初始数。样品中金黄色葡萄球菌细胞的数量和在含抗生素的选择性培养基中孵育数小时后金黄色葡萄球菌细胞的数量。只有当样本含有MRSA时，S.金黄色葡萄球菌细胞数量的抗生素的存在。这种基于表型生长的方法优于基于基因型核酸的测试的优点在于，其可以应用于任何类型的微生物和任何抗生素。具体目标是：（1）发展S。金黄色葡萄球菌特异性颗粒试剂和MRSA筛查方法;（2）开发包括成像仪器和含试剂盒的自动原型系统;（3）证明测定性能，并将其与使用临床样本的培养和核酸扩增参考方法进行比较。实现这些特定目标应证明第2阶段项目的合理性，该项目将重点关注将MRSA检测扩展到其他样本类型（例如，伤口、软组织、血液），开发用于引起医院获得性感染的其它重要因子的测试（例如，万古霉素耐药肠球菌、C. difficile），并开发用于MRSA筛查的预商业化原型仪器/消耗品系统。除了检测耐药微生物的价值外，该系统还具有其他重要细胞检测应用的商业潜力，包括检测病毒感染细胞，CD 4+细胞（用于监测HIV状态），食品病原体和药物发现。公共卫生相关性用于筛查耐药细菌的商业化MultiPath系统将有助于降低医院获得性感染的发生率。每年发生的约200万例医院获得性感染导致近20，000人死亡，每年花费医疗保健系统约300亿美元。新系统将使更多的医院能够实施快速检测，从而改善感染控制，降低医院获得性感染率。

DESCRIPTION (provided by applicant): We propose to develop a novel testing platform to enable rapid, ultrasensitive, accurate, user-friendly, and cost-effective screening for the antibiotic resistant bacteria that frequently cause serious hospital acquired infections. Every year, nearly 100,000 deaths result from 2 million serious hospital acquired infections at an estimated cost of $30.5B. About 20,000 of these fatalities are caused by methicillin-resistant Staphylococcus aureus bacteria (MRSA). Both the rate of hospital acquired infections and the spread of MRSA have increased dramatically in the last 30 years. Many individuals now carry MRSA on their bodies, even when healthy. When MRSA carriers are hospitalized the resistant microbe can cause serious infections for the carrier and others in the hospital. Recent studies have shown that hospitals can substantially decrease the occurrence of hospital acquired infections by screening admitted patients for MRSA and then treating them using rigorous infection control procedures including isolation. Traditional microbiological methods for screening patients for MRSA are very slow, requiring several days, and are therefore incompatible with rapid identification and isolation of MRSA carriers. New rapid MRSA tests based on nucleic acid amplification are used for MRSA screening at some sites. However these tests are expensive, complex and thus not currently practical for large scale screening in most hospitals. We aim to develop a novel rapid, sensitive, and easy-to-use system for large scale cost-effective MRSA screening. The system's proprietary technology uses low-cost non-magnified digital imaging to count individual S. aureus cells specifically tagged with highly fluorescent particles. The test determines the initial number of S. aureus cells in the sample and the number of S aureus cells after incubation for several hours in antibiotic-containing selective media. Only if the sample contains MRSA, will there be a significant in- crease in S. aureus cell number in the presence of antibiotic. An advantage of this phenotypic growth-based approach over genotypic nucleic acid-based tests is that it can be applied to any type of microbe and any anti- biotic. The Specific Aims are to (1) develop S. aureus-specific particle reagents and the MRSA screening as- say method; (2) develop an automated prototype system including an imaging instrument and a reagent- containing cartridge; and (3) demonstrate assay performance and compare it to the culture and nucleic acid amplification reference methods using clinical samples. Achieving these Specific Aims should justify a Phase 2 project that will focus on extending the MRSA assay to other sample types (e.g., wound, soft tissue, blood), developing tests for other important agents that cause hospital acquired infection agents (e.g., vancomycin resistant Enterococcus, C. difficile), and developing a pre-commercial prototype instrument/consumable system for MRSA screening. Besides its value for detecting resistant microbes, the system has commercial potential for other important cellular detection applications including detecting virally infected cells, CD4+ cells (for monitoring HIV status), food pathogens, and in drug discovery. PUBLIC HEALTH RELEVANCE The commercialized MultiPath system for screening for resistant bacteria will help lower the rate of hospital acquired infections. The approximately 2 million hospital acquired infections that occur per year cause nearly 20,000 deaths and cost the healthcare system about $30B a year. The new system will enable more hospitals to implement rapid testing, which in turn leads to improved infection control and lower hospital acquired infection rates.