MALDI-TOF MS分析大肠菌群不合格餐(饮)具中的微生物污染情况

Analysis of Microbial Contamination in Catering Utensils with Coliform Failure by MALDI-TOF MS

为了解餐(饮)具中大肠菌群污染情况及被污染的餐(饮)具是否有致病风险,对大肠菌群项目不合格餐(饮)具中的微生物进行菌种鉴定。将餐(饮)具复发酵阳性的培养物转接伊红美蓝琼脂平板进行分离,利用基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)技术对28批不合格餐具中分离到的62株野生菌株的单个菌落进行精确鉴定,鉴定率为93.55%,鉴定结果均与自动微生物生化鉴定仪鉴定结果一致。主要鉴定出阪崎克罗诺杆菌、丙二酸盐克罗诺杆菌、大肠埃希氏菌、肺炎克雷伯菌、产酸克雷伯菌、弗氏柠檬酸杆菌、阴沟肠杆菌等10种微生物。其中存在致病风险的微生物比例达68.97%,而28批次不合格餐(饮)具中存在致病风险的达26批次,占比92.86%。MALDI-TOF MS技术能同时且快速准确地鉴定出餐(饮)具中存在的不同微生物,而大肠菌群不合格餐(饮)具存在较高的致病风险,需加强餐(饮)具卫生管理与监测。

In order to understand the contamination situation of coliform bacteria in catering utensils and whether the contaminated catering utensils pose a risk of disease,the microbial species in catering utensils that failed in the coliform bacteria group project were identified.The positive cultures were transferred to eosin methylene blue agar plates for isolation,and matrix-assisted laser resolved ionization time-of-flight mass spectrometry(MALDI-TOF MS)was used to accurately identify the single colonies of 62 wild strains of microorganisms isolated from 28 batches of unqualified tableware,with the identification rate of 93.55%,which was in line with that of the automated microbial biochemistry identification instrument.It mainly identified 10 kinds of microorganisms,including Cronobacter sakazakii,Cronobacter malonate,Escherichia coli,Klebsiella pneumoniae,Klebsiella acidogenes,Citrobacter freundii,and Enterobacter cloacae,etc.Among them,the proportion of microorganisms with disease-causing risk reached 68.97%,while 26 out of 28 batches of unqualified catering utensils had disease-causing risk,accounting for 92.86%.MALDI-TOF MS technology can quickly and accurately identify different microorganisms present in catering utensils at the same time,and unqualified coliform bacteria in catering utensils pose a higher risk of disease.Therefore,it is necessary to strengthen the hygiene management and monitoring of catering utensils.