Institute of Life Technologies, University of Applied Sciences, HES-SO Valais/Wallis, Sion 1950, Switzerland.
Mabritec AG, Food Technology, Riehen 4125, Switzerland.
Toxins (Basel). 2019 Feb 9;11(2):101. doi: 10.3390/toxins11020101.
Routine identification of pathogens by MALDI-TOF MS (matrix-assisted laser desorption ionisation time-of-flight mass spectrometry) is based on the fingerprint of intracellular proteins. This work evaluated the use of MALDI-TOF MS for the identification of extracellular pathogen factors. A Staphylococcus aureus isolate from a food contaminant was exponentially grown in liquid cultures. Secreted proteins were collected using methanol⁻ chloroform precipitation and analysed by MALDI-TOF MS. A main peak m/z 28,250 was demonstrated, which was identified as S.aureus enterotoxin type B (SEB) by using the pure authentic SEB reference of 28.2 kDa and by amino acid sequence analysis. SEB was also detected in this intact form following pasteurization and cooking treatments. Further application of the elaborated MALDI-TOF MS protocol resulted in the detection of SEA at m/z 27,032 and SEC at m/z 27,629. In conclusion, a simple sample preparation from S.aureus cultures and an easy-to-perform identification of pathogen factors SE in intact form represents a promising next-generation application of MALDI-TOF MS.
基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）常规鉴定病原体基于细胞内蛋白质指纹图谱。本研究评估了 MALDI-TOF MS 用于鉴定细胞外病原体因子的用途。从食品污染物中分离出一株金黄色葡萄球菌，在液体培养基中进行指数生长。使用甲醇-氯仿沉淀法收集分泌蛋白，并通过 MALDI-TOF MS 进行分析。显示出一个主要的峰 m/z 28250，通过使用 28.2 kDa 的纯 SEB 参考标准和氨基酸序列分析，将其鉴定为金黄色葡萄球菌肠毒素 B（SEB）。巴氏杀菌和烹饪处理后也以完整形式检测到 SEB。进一步应用精心设计的 MALDI-TOF MS 方案，检测到 m/z 27032 的 SEA 和 m/z 27629 的 SEC。总之，从金黄色葡萄球菌培养物中进行简单的样品制备，并以完整形式轻松鉴定 SE 病原体因子，代表了 MALDI-TOF MS 的一种很有前途的下一代应用。
