基于16S rDNA序列、MALDI-TOF-MS和VITEK的沙门氏菌和金黄色葡萄球菌的鉴定

Identification of Salmonella and Staphylococcus aureus Using 16S rDNA Sequencing,MALDI-TOF-MS and VITEK System

沙门氏菌和金黄色葡萄球菌广泛存在于食品及环境中,对食品安全造成一定的威胁。在食源性致病菌检测过程中,选择合适的方法不仅可以缩短时间,节省人力物力,还能更好地溯源。选取210株沙门氏菌和18株金黄色葡萄球菌,使用16S rDNA序列测定、基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)和VITEK全自动细菌鉴定系统对其鉴定,使用R软件包(v3.6.1)对鉴定结果进行统计和相关性分析,比较3种方法的鉴定水平和效率。结果表明:3种方法均可将210株沙门氏菌(100.0%)鉴定到属水平;16S rDNA序列测定方法可将18株(100.0%)金黄色葡萄球菌鉴定到属水平,可将其中15株(83.3%)菌鉴定到种水平;MALDI-TOF-MS和VITEK可将18株金黄色葡萄球菌(100.0%)鉴定到种水平。除16S rDNA序列测定方法外,其余2种方法对金黄色葡萄球菌和沙门氏菌的鉴定水平相同,而MALDI-TOF-MS鉴定所需时间最短、效率最高。

Salmonella and Staphylococcus aureus are prevalent in food and environment, and pose certain threats to food safety. During foodborne pathogens identification, appropriate identification method choosing can shorten time, save manpower and material resource, increase the trace ability. In this study, 210 Salmonella and 18 Staphylococcus aureus strains acquired in our previous study were further identified using 16S rDNA sequencing, MALDI-TOF-MS and VITEK automatic microbiological identification system. Identification level and efficiency of each method and the correlation among the identification results were statistically analyzed using R software(v3.6.1). The results indicated 210(100.0%)Salmonella strains could be identified into genus level via the 3 methods, 18(100.0%) Staphylococcus aureus strains could be identified into species level by any of MALDI-TOF-MS and VITEK. When 16S rDNA sequencing method was used, 18(100.0%) Staphylococcus aureus could be identified to genus level, and 15(83.3%) strains could be identified into species level. In addition to 16S rDNA sequencing method, the other 2 methods had the same identification ability for Staphylococcus aureus and Salmonella, however, time usage of MALDI-TOF-MS was the shortest.