Development and Evaluation of Novel Applied Diagnostic Platforms for Clinical Microbiology

传统的微生物工作是缓慢的，有时不准确，依赖于表型培养鉴定，然后进行抗菌药物敏感性测试。基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）和实时分子检测（抗菌素耐药基因微阵列）等新技术提高了临床微生物实验室的诊断能力，并为研究和开发创造了一个令人兴奋的领域。鉴于这些平台产生的深入和高度准确（有时复杂）的结果，需要进行仔细的详细分析，以更好地了解所鉴定微生物的临床意义和检测到的耐药机制。 在本财政年度，我们对HardyCHROM CRE培养基用于检测监测培养物中产碳青霉烯酶微生物的临床性能进行了一项大型回顾性分析。数据显示阳性预测值范围为8-56%，具体取决于所应用的碳青霉烯类耐药微生物的定义，该定义在各州和国家指南之间存在差异。这对应用感染控制实践和针对潜在临床感染的抗菌剂选择具有巨大影响。我们还对用于检测碳青霉烯酶的三种表型检测方法进行了比较评价，并对MALDI-TOF MS的性能和准确性进行了回顾性分析，并直接从阳性血培养物中进行了药敏试验。后者为临床微生物学报告提供了有用的结果，同时等待标准化的检测结果。质量改进项目包括血培养体积监测方法（重量与虚拟系统）的前瞻性比较评价、多重胃肠道病原体组与传统方法的比较分析以及新型疗法产品无菌检测系统的大型比较评估（传统USP<71>手动方法与自动化Bactec FX系统和BacTAlert Dual-T系统）。

Traditional microbiological work up is slow and sometimes inaccurate, relying on phenotypic culture identification followed by antimicrobial susceptibility testing. Newer technologies, such as matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and real-time molecular detection (antimicrobial resistance genes microarrays) have advanced the diagnostic capabilities of clinical microbiology laboratories and have created an exciting field for research and development. Given the in-depth and highly accurate (sometimes complex) results that are produced by such platforms, careful detailed analyses are required to better understand the clinical significance of the organisms identified and the resistance mechanisms detected. During this fiscal year, we performed a large retrospective analysis on the clinical performance of HardyCHROM CRE media for the detection of carbapenemase-producing organisms from surveillance cultures. Data showed a positive predictive value ranging 8-56% depending on the definition carbapenem resistant organisms applied which varies between states and national guidelines. This has a tremendous effect on applied infection control practices and antimicrobial choices in response to a potential clinical infection. We also performed a comparative evaluation of three phenotypic assays for the detection of carbapenemases, as well as a retrospective analysis on the performance and accuracy of MALDI-TOF MS and susceptibility testing directly from positive blood cultures. The latter has provided informative results for clinical microbiology reporting while awaiting standardized testing results. Quality improvement projects have included a prospective comparative evaluation of blood culture volume monitoring methods (weight vs virtual system), comparative analysis of a multiplex gastrointestinal pathogen panel with traditional methods, and a large comparative assessment of product sterility testing systems for novel therapies (traditional USP<71> manual method vs automated Bactec FX system and BacTAlert Dual-T system).