Development and Evaluation of Novel Applied Diagnostic Platforms for Clinical Microbiology

传统的微生物检测速度很慢，有时甚至不准确，依赖于表型培养鉴定和药敏试验。较新的技术，如基质辅助激光解吸电离飞行时间质谱仪(MALDI-TOF MS)和实时分子检测(抗菌素耐药基因芯片)，提高了临床微生物学实验室的诊断能力，创造了一个令人兴奋的研发领域。考虑到这种平台产生的深入和高度准确(有时是复杂的)结果，需要仔细详细的分析，以更好地理解所确定的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HardyCHROMCRE培养基从监测培养中检测碳青霉烯酶产生菌的临床表现进行了大规模的回顾分析。数据显示，阳性预测值在8-56%之间，这取决于所应用的碳青霉烯耐药生物体的定义，这在各州和国家指南之间有所不同。这对应用的感染控制做法和针对潜在临床感染的抗菌剂选择产生了巨大影响。我们还对三种检测碳青霉烯酶的表型方法进行了比较评价，并对MALDI-TOF MS的性能和准确性以及直接从阳性血培养中进行的药敏试验进行了回顾分析。后者在等待标准化检测结果的同时，为临床微生物学报告提供了有用的结果。质量改进项目包括血培养容量监测方法(重量和虚拟系统)的前瞻性比较评估，多重胃肠道病原体小组与传统方法的比较分析，以及针对新疗法的产品无菌测试系统的大型比较评估(传统USP&lt；71&gt；手动方法与自动Bactec FX系统和BacTAlert双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).