基质辅助激光解吸电离飞行时间质谱在李斯特菌检测和鉴定中的应用

为建立食品中各种李斯特菌的快速检测和鉴定方法,应用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)对单增李斯特菌、绵羊李斯特菌、英诺克李斯特菌、威尔斯李斯特菌和格氏李斯特菌5种李斯特菌进行检测,并与传统的生化鉴定方法(VITEK 2)和聚合酶链式反应(PCR)方法检测结果进行比较;用不同培养基和不同培养时间培养的单增李斯特菌对该方法进行检测,还对60份人工感染5种李斯特菌的食品样品分别进行MALDI-TOF-MS、PCR以及传统生化方法的检测和鉴定。结果表明:MALDI-TOF-MS能够快速、可靠地区分上述5种李斯特菌,而且具有很好的稳定性和重复性,在检测时间、重复性和准确性方面的总体表现优于传统生化鉴定方法。MALDI-TOF-MS技术适用于对李斯特菌等食源性病原菌进行高通量、低成本的快速鉴定。

Detection and Identification of Listeria Species by Matrix-assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

Five type strains of Listeria species such as Listeria monocytogenes,L.ivanuii,L.innocua,L.welshimeri and L.grayi were detected and identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF-MS).The results were compared with those detected by conventional techniques(VITEK-2) and PCR at the same time.L.monocytogenes cultured in different media with various cultivation time was evaluated.Moreover,60 artificial food samples infected with 5 Listeria species were also tested by MALDI-TOF-MS,conventional techniques and PCR.The results indicated that MALDI-TOF-MS was a fast and reliable method for the identification of Listeria species,which also had the characteristics of excellent stability and reproducibility.The overall performance of MALDI-TOF-MS revealed significant advantages compared with conventional biochemical detection systems.Therefore,MALDI-TOF-MS is suitable for high-throughout and rapid screening at low cost during the detection and identification of foodborne pathogenic bacteria such as Listeria species.