葡萄球菌属细菌数值鉴定系统的研制与效果评价

Development and performance evaluation of a numerical identification system for Staphylococcus

摘要:

【背景】 葡萄球菌属(Staphylococcus)细菌是临床感染中的重要病原体，不同种的葡萄球菌对人体危害程度有所不同，因此对葡萄球菌属分型是临床医学中精准治疗的理论基础。现有的不同葡萄球菌种间分型技术存在成本高、操作烦琐、准确性低等缺点，目前仍以常规分离鉴定技术为主。【目的】 开发一种简便、可靠的葡萄球菌属生化分型鉴定方法，建立葡萄球菌属细菌数值鉴定系统并对其鉴定性能进行评价。【方法】 将鉴定系统所需的生化反应配方浓缩整合到一组注塑件中制得鉴定条，结合数值鉴定软件构建葡萄球菌属细菌数值鉴定系统；以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)法为参考标准，利用从农贸样品中选择性分离的葡萄球菌对其鉴定准确度进行验证。【结果】 对训练集的370株葡萄球菌进行生化试验，创建了用于鉴别葡萄球菌属内26个种/亚种的生化反应阳性概率数据库。将结果导入Identax软件构建葡萄球菌属细菌数值鉴定系统，并制定相关标准对鉴定结果进行评价。通过对测试集的422株葡萄球菌属分离株进行生化数值鉴定，其结果与MALDI-TOF MS方法的总鉴定一致率为91%。【结论】 本研究开发的葡萄球菌属细菌数值鉴定系统操作简便、价格低廉、准确率高，可为基层实验室和食品安全检测提供实验依据，具有良好的临床应用推广前景。

Abstract:

[Background] Bacteria of Staphylococcus are major pathogens in clinical infections. Different species of Staphylococcus cause varying degrees of harm to the human body. Therefore, typing of Staphylococcus provides a theoretical basis for precise treatment in clinical medicine. The existing typing techniques for different Staphylococcus species have disadvantages such as high costs, complicated operation, and low accuracy. Therefore, the conventional isolation and identification techniques are still mainly used at present. [Objective] To develop a simple and reliable biochemical typing method, establish a numerical identification system for Staphylococcus bacteria, and evaluate the identification performance of this system. [Methods] We integrated the biochemical reaction formulas required for the identification system into a set of injection molded parts to produce identification strips. A numerical identification system for Staphylococcus was constructed in combination with numerical identification software. The identification accuracy of the system was evaluated with Staphylococcus selectively isolated from agricultural trade samples as a reference standard and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) as the reference method. [Results] Biochemical tests were conducted on 370 strains of Staphylococcus in the training set, and a positive probability database of biochemical reactions for identifying 26 species/subspecies of Staphylococcus was created. The results were imported into the Identax software to construct a numerical identification system for Staphylococcus, and relevant standards were established to evaluate the identification results. The biochemical numerical identification of 422 isolates of Staphylococcus in the test set showed the result consistency rate of 91% with the MALDI-TOF MS method. [Conclusion] The numerical identification system for Staphylococcus that is developed in this study has simple operation, a low cost, and high accuracy. It can provide an experimental basis for primary-level laboratories and food safety testing and has good prospects for clinical application and promotion.