Department of Clinical Laboratory, Huanggang Central Hospital, Huanggang, Hubei Province, 438021, China.
Department of Spine Surgery and Musculoskeletal Tumor, Zhongnan Hospital of Wuhan University, 430071, Wuhan, China.
Med Mycol. 2022 Mar 17;60(4). doi: 10.1093/mmy/myac018.
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been successfully applied to identify microorganisms. However, unlike bacteria and yeast where identification results can be obtained rapidly and accurately by using a simple direct-coating pretreatment method, the traditional pretreatment methods for filamentous fungi are more complex, involving ethanol, formic acid, acetonitrile, and a protein extraction process by centrifugation, i.e., the EtOH-FA full extraction. This cumbersome pretreatment for filamentous fungi is a major reason for the lack of widespread use of MALDI-TOF MS for the identification of filamentous fungi in clinical settings. The present study describes an alternative method, the FA-sandwich, and demonstrates that the approach is efficient and effective. 148 clinical filamentous fungal isolates collected from three large general hospitals in Hubei Province, China, were processed by the FA-sandwich method and identified by two MALDI-TOF MS platforms, Autof ms and Vitek MS. The FA-sandwich allowed a 93.9% species-level identification with Autof ms, and 97.3% species-level identification rates were found for Vitek MS when the IVD, the RUO and in-house databases are used in combination. Further comparison of the ease of FA-sandwich with the EtOH-FA full extraction showed that the FA-sandwich is a more convenient, time- and reagent-saving, and sensitive pretreatment method. These findings indicate that the FA-sandwich method is suitable for pretreating filamentous fungi followed by MALDI-TOF MS identification in clinical microbiology laboratories.
The FA-sandwich method improves the efficiency of identification of filamentous fungi using MALDI-TOF MS while ensuring identification accuracy. The method is easy to perform and very suitable for detecting mold in the microbiology laboratory with the goal of promoting timely and accurate therapies.
基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）已成功应用于微生物鉴定。然而，与细菌和酵母不同，这些微生物可以通过简单的直接涂层预处理方法快速准确地获得鉴定结果，丝状真菌的传统预处理方法则更为复杂，需要经过乙醇、甲酸、乙腈以及离心提取蛋白质的过程，即 EtOH-FA 全提取。丝状真菌这种繁琐的预处理方法是 MALDI-TOF MS 在临床环境中广泛用于丝状真菌鉴定的主要障碍。本研究描述了一种替代方法，即 FA-sandwich，并证明该方法是高效且有效的。从中国湖北省的三家大型综合医院采集了 148 株临床丝状真菌分离株，通过 FA-sandwich 方法进行处理，并使用 Autof ms 和 Vitek MS 两种 MALDI-TOF MS 平台进行鉴定。FA-sandwich 方法与 Autof ms 联合使用时，可实现 93.9%的种水平鉴定；与 IVD、RUO 和内部数据库联合使用时，Vitek MS 可实现 97.3%的种水平鉴定率。进一步比较 FA-sandwich 与 EtOH-FA 全提取的简易程度，表明 FA-sandwich 是一种更方便、省时、省试剂且灵敏的预处理方法。这些发现表明，FA-sandwich 方法适用于丝状真菌的 MALDI-TOF MS 鉴定前处理，在临床微生物学实验室中具有广泛的应用前景。
FA-sandwich 方法在确保鉴定准确性的同时，提高了 MALDI-TOF MS 鉴定丝状真菌的效率。该方法易于操作，非常适合微生物实验室检测霉菌，以促进及时、准确的治疗。
