基于流式分析技术的奶粉中金黄色葡萄球菌活菌快速定量检测方法研究

Rapid and Quantitative Detection of Viable Staphylococcus aureus in Milk Powder Based on Flow Cytometry Technology

建立了一种奶粉中金黄色葡萄球菌活菌快速定量检测新方法。以异硫氰酸荧光素偶联的金黄色葡萄球菌多克隆抗体特异性标记金黄色葡萄球菌,再通过碘化丙啶来区分死活菌,建立流式分析法,并应用于奶粉样品中金黄色葡萄球菌活菌定量检测。结果表明,该流式分析法特异性好;当人工污染奶粉样品中金黄色葡萄球菌浓度在2.72×10^(3)~2.80×10^(8) CFU/mL之间时,流式检测方法与平板计数方法检测结果一致;该方法的检测限为2.72×10^(3) CFU/mL,检测时间为35 min。该方法具有快速和高效的优点,在食源性致病菌的快速检测和预警中具有良好的应用前景。

A flow cytometry(FCM)-based method for rapid and quantitative detection of viable Staphylococcus aureus in milk powder was developed.Staphylococcus aureus was labelled with Fluorescein isothiocyanate(FITC)by reacting with the anti-Staphylococcus aureus polyclonal antibody(FITC),then dead and viable bacteria were distinguished by membrane-impermeable dyes Propidium Iodid(PI).The FCM-based method was established and applied to the quantitative detection for Staphylococcus aureus in milk powder samples.The results showed that the FCM-based method exhibited high specificity towards Staphylococcus aureus.When the concentration of Staphylococcus aureus in artificially contaminated milk powder samples ranged from 2.72×10^(3)~2.80×10^(8) CFU/mL,the FCM-based method and plate-based method yielded the same result,and the detection limit of the method is 2.72×10^(3) CFU/mL,and total time is 35 min.The method is rapid and efficient,so it has a great application prospect in rapid screening and monitoring of foodborne pathogens.