基质辅助激光解吸电离飞行时间质谱法对环境中芽孢杆菌的鉴定及溯源

目的 使用基质辅助激光解吸电离飞行时间质谱技术 (matrix assisted laser desorption lionization-time of flight mass spectrometer, MALDI-TOF MS),对芽孢杆菌进行快速鉴定和聚类分析,用于研究MALDI-TOF MS对芽孢杆菌溯源的可行性。方法 对实验菌株纯化培养后,使用甲酸提取法提取实验菌株蛋白,并使用MALDI-TOF MS,对22株环境分离菌株和1株标准菌株(CGMCC(B)1.1086)进行鉴定。进一步采集22株实验菌株的蛋白质指纹图谱,使用SARAMIS软件,对实验菌株进行聚类分析。结果 经鉴定,标准菌株(CGMCC(B)1.1086)的鉴定结果可信度为99.9%。22株环境菌均为芽孢杆菌,其中,6株菌鉴定到属水平,16株菌鉴定到种水平。在相似水平为80%的条件下,22株芽孢杆菌分为22个分支。结论 可以使用MALDI-TOF MS对芽孢杆菌进行快速鉴定与分型,对于微生物溯源有重要意义,能够满足食品检测及溯源的需求。

Identification and traceability of Bacillus in the environment by matrix-assisted laser desorption lionization-time of flight mass spectrometry

Objective Establishment of matrix assisted laser desorption lionization-time of flight mass spectrometer technology for rapid identification and cluster analysis of Bacillus, to study the feasibility of MALDI-TOF MS for traceability of Bacillus. Methods After the experimental strains were purified and cultured, the protein of the experimental strains was extracted by formic acid extraction method, and using MALDI-TOF MS, 22 isolated environmental strains and 1 standard strain (CGMCC(B)1.1086) were identified. Furthermore, the protein fingerprints of 22 experimental strains were collected, and the experimental strains were clustered using SARAMIS software. Results After identification, the credibility of the identification result of the standard strain (CGMCC(B)1.1086) is 99.9%. The 22 environmental bacteria identified are all Bacillus, of which 6 strains were identified to the genus level and 16 strains were identified to the species level. At a similar level of 80%, 22 strains of Bacillus were divided into 22 branches. Conclusion MALDI-TOF MS, as a new, fast and accurate microbial identification technology, realizes the rapid identification and typing of bacillus, is of great significance for microbial traceability, and can meet the needs of food safety testing.