Multicenter Studies to Evaluate the Performance of MALDI-TOF MS for Fungal Identification

传统的霉菌鉴定具有挑战性、繁琐和耗时，依赖于培养的非特定表型特征或昂贵和专门的DNA测序方法。MALDI-TOF MS使世界各地的临床微生物学实验室发生了革命性的变化，使细菌和酵母的快速鉴定成为可能。然而，由于开发有效的蛋白质提取方法的技术挑战和临床综合数据库的有限，这项技术还没有容易地应用于霉菌鉴定。 最近，我们开发和优化了一种简单的霉菌蛋白质提取程序，并构建了一个由来自90个属220个物种的410个单独分离物组成的高度严格的数据库，用于MALDI-TOF MS快速鉴定霉菌。NIH霉菌数据库是迄今为止开发的最全面的霉菌鉴定数据库，填补了临床微生物学领域的巨大诊断空白。NIH霉菌数据库现已与全球100家临床微生物学实验室共享，旨在通过提供更快的鉴定(在生长检测后30分钟内而不是数周内)来改进侵袭性真菌感染的诊断，从而指导最佳的抗真菌治疗。 在本财年，开展了一项八中心的国家对照研究，以评估两个真菌数据库(NIH霉菌数据库和布鲁克真菌数据库)与80个临床霉菌分离株的临床表现和准确性。此外，还与另一家美国机构开展了一项合作项目，以调查不同培养条件(培养基、培养时间、固体与液体)对两个真菌数据库的影响。这两项研究都在进行中，预计研究结果将突出全球临床微生物学实验室统一实施MALDI-TOF MS进行常规霉菌鉴定所需的重要(以前未确定的)因素。这反过来将使侵袭性真菌感染的更快诊断和有针对性的治疗策略成为可能。

Traditional identification of molds is challenging, cumbersome, and time-consuming, relying on non-specific phenotypic characteristics from culture or expensive and specialized DNA sequencing methods. MALDI-TOF MS has revolutionized clinical microbiology laboratories worldwide, enabling rapid identification of bacteria and yeast. This technology, however, has not been readily applied to mold identification due to technical challenges in developing an efficient protein extraction method and the limited availability of clinically comprehensive databases. Recently, we developed and optimized a simple protein extraction procedure for molds and constructed a highly stringent database comprising 410 individual isolates representing 90 genera and 220 species for the rapid identification of molds by MALDI-TOF MS. The NIH Mold Database is the most comprehensive database developed to date for mold identification and has filled a huge diagnostic gap in the field of clinical microbiology. The NIH Mold Database has now been shared with >100 clinical microbiology laboratories worldwide in an effort to improve the diagnosis of invasive fungal infections by providing faster identification (within 30 minutes of growth detection as opposed to weeks) that in turn can guide optimal antifungal therapy. During this fiscal year, an eight-center national controlled study was undertaken to evaluate the clinical performance and accuracy of two fungal databases (the NIH Mold Database and the Bruker Fungi Database) against 80 clinical mold isolates. In addition, a collaborative project was undertaken with another US institution to investigate the effects of different culture conditions (media, time of incubation, solid vs. liquid media) against both fungal databases. Both studies are ongoing and it is envisaged that the findings will highlight important (previously undetermined) factors required for the uniform implementation of MALDI-TOF MS for the routine mold identification in clinical microbiology laboratories worldwide. This in turn will enable faster diagnosis and targeted therapeutic strategies for invasive fungal infections.