基质辅助激光解吸电离飞行时间质谱与VITEK和rpoB基因测序三种方法对食品中葡萄球菌鉴定效果的比较

目的 比较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)、rpoB基因测序和VITEK 2 Compact三种方法对葡萄球菌的鉴定效果。方法 同时采用三种方法对实验室保存的从食品中分离的59株葡萄球菌进行鉴定。结果 MALDI-TOF MS法和rpoB基因测序法一致性达100.00%,与VITEK 2 Compact法的一致性为83.05%(49/59)。7株菌因超出VITEK 2 Compact鉴定范围而鉴定错误。MALDI-TOF MS法可快速将59株菌准确鉴定为17种葡萄球菌,鉴定分值与细菌种类相关。金黄色葡萄球菌的鉴定分值最高(>2.300),松鼠葡萄球菌、鱼发酵葡萄球菌和琥珀葡萄球菌的鉴定分值相对较低(1.700～2.000)。结论 相比rpoB基因测序法和VITEK 2 Compact法,MALDI-TOF MS法更加快速准确。为达到更好的鉴定效果,现有数据库仍需进一步优化。

Comparison of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, VITEK and rpoB gene sequencing three methods for identification of Staphylococci in food

Objective To compare the identification effect of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, rpoB gene sequencing and VITEK 2 Compact on Staphylococci. Methods Three methods were used to identify 59 isolates of Staphylococci from food simultaneously. Results The result consistency of MALDI-TOF MS and rpoB gene sequencing was 100.00%, while the consistency of MALDI-TOF MS with VITEK 2 Compact was 83.05% (49/59). Seven isolates were misidentified by VITEK 2 Compact because of out of identification range. The MALDI-TOF MS method could quickly identify 59 strains as 17 species of Staphylococci, and the identification score was related to the species. The identification score of Staphylococcus aureus is the highest (>2.300), and the identification score of Staphylococcus squirrel, S.piscifermentans and S.succinus was relatively low (1.700-2.000). Conclusion Compared with rpoB gene sequencing and VITEK 2 Compact method, MALDI-TOF MS method is more rapid and accurate. In order to achieve a better identification effect, the existing database still needs to be further optimized.