肉类食品中大肠杆菌快速检验即用型质控样品研制

Development of Ready-to-Use Quality Control Samples for Rapid Detection of Escherichia coli in Meat and Meat Products

为实现肉类食品中大肠杆菌快速检验,研制出大肠杆菌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)检验即用型质控样品,可以直接溶解使用,无需再次培养,并系统分析了质控样品的均匀性和稳定性。结果表明:经筛选得到冻干基质最佳条件,质控样品存活率均在90%以上;质控样品培养计数结果F=0.567,小于临界值,证明均匀性好;质控样品在37℃和25℃环境下放置14 d后菌株计数稳定,在-20℃和4℃环境下贮藏28 d复苏率分别为101.5%和99.6%,在37℃和-20℃环境下贮藏28 d后的MALDI-TOF-MS检测结果仍保持一致,表明样品稳定性好,满足作为质控样品的要求。

This paper developed a ready-to-use quality control sample which can be directly used without secondary culture for the rapid detection of Escherichia coli in meat and meat products by matrix assisted laser desorption/ionization time-offlight mass spectrometry(MALDI-TOF-MS).The sample was evaluated for homogeneity and stability.The results showed that the survival rate of the quality control sample prepared using the selected cryoprotectant was above 90%.The culture count result of the quality control sample(F=0.567)was less than the critical value,suggesting good uniformity.The quality control sample was stable for 14 days at 37 and 25℃,and the resuscitation rates were 101.5%and 99.6%at−20 and 4℃for 28 days,respectively.After 28 days of storage at 37 and−20℃,the results of MALDI-TOF-MS were consistent,indicating that the developed sample had good stability and met the requirements of quality control samples.