Abstract: The rapid identification of Salmonella, a significant foodborne pathogen, is of significant importance. To establish a new method for identifying Salmonella based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), this study optimized culture medium type, incubation time, bacterial lysis methods, and instrumental parameters. The results showed that compared to the national standard method GB/T 33682-2025 General microorganism identification method with matrix-assisted laser desorption/ionization time of flight mass spectrometry, the recovery rate increased from 54.7% to 84.7% after replacing the culture medium with nutrient agar. Increasing the incubation time from 24 to 48 h increased the average identification score by 7.0%, from 2.203 to 2.355. Optimizing lysis methods elevated the average identification score by 19.0%, from 1.898 to 2.259. When the instrumental parameters were adjusted to 50% laser energy and a laser wavelength of 370 nm, the average identification score increased to 2.211. Compared to its original version specified in GB/T 33682-2025, the established MALDI-TOF/TOF MS method exhibited improved accuracy and reliability in Salmonella identification.

Key words: Salmonella; matrix-assisted laser desorption ionization time-of-flight mass spectrometry; method optimization; rapid identification

摘要： 沙门氏菌作为重要的食源性致病菌，对其开展快速鉴定具有重要意义。基于基质辅助激光解吸电离飞行时间质谱（matrix-assisted laser desorption ionization time-of-flight mass spectrometry，MALDI-TOF MS）技术，通过对培养基种类、培养时间、菌体裂解方法及仪器参数进行优化，建立沙门氏菌鉴定的MALDI-TOF/TOF MS方法。结果表明，与GB/T 33682—2025《基质辅助激光解吸电离飞行时间质谱鉴别微生物方法通则》中的方法相比，将培养基优化为营养琼脂培养基后，回收率由54.7%上升至84.7%；培养时间由24 h延长至48 h后，平均鉴定分值由2.203提升至2.355，提高7.0%；优化裂解方式后，平均鉴定分值由1.898提高至2.259，提升19.0%；将仪器参数调整为激光能量50%、激光波长370 nm后，平均鉴定分值提高至2.211。对GB/T 33682—2025方法进行优化后，所建立的MALDI-TOF/TOF MS方法提高了沙门氏菌鉴定的准确度与可信度，可以作为现行国标方法的有效补充。

关键词: 沙门氏菌；基质辅助激光解吸电离飞行时间质谱；方法优化；快速鉴定