高通量微生物显色法快速检测动物源性食品中抗生素残留

建立一种采用高通量微生物显色法对动物源性食品中抗生素残留进行筛检,再结合高效液相色谱-串联质谱(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)法对阳性样品进行复测的分析检验方法。本方法利用嗜热脂肪芽孢杆菌(Bacillus sterothermophilus)作为指示菌,制备96微孔板,可同时对不同类别多种抗生素进行联合检测。结果表明:该微生物显色法操作简便、快捷,成本低,结果准确且易判断,选取pH 7.4磷酸盐缓冲液进行提取,以反应液150μL、菌液50μL(初始OD_(600 nm)为0.4左右)、样品提取液100μL作为检测体系,检测效果最佳,对动物源性食品中氨基糖苷类检出限为60μg/kg,β-内酰胺类检出限为20~40μg/kg,大环内酯类检出限为60~80μg/kg,四环素类检出限为40~60μg/kg,符合国内外对抗生素残留限量的要求。对60份动物源性样品进行检测,其结果与HPLC-MS/MS复测结果一致,说明该微生物法稳定性良好,可用于动物源性食品中抗生素残留的初筛检测。

Rapid and High-Throughput Detection of Antibiotic Residues in Animal-Derived Food Samples by Microbial Chromotest

A new rapid and high-throughput microbial chromogenic assay was developed to analyze antibiotic residues in animal-derived food samples. The positive samples were further confirmed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. Bacillus sterothermophilus was used as an indicator strain to produce a 96-well microplate for detecting a variety of antibiotics simultaneously. The results showed that the microbial assay was simple and cheap, and gave easy-to-interpret results. After extraction with phosphate buffer at pH 7.4, muscle samples were detected using a chromogenic assay system consisting of the reactant solution (150 μL), bacterial suspension (50 μL) with an initial optimal density (OD600 nm) of around 0.4, and the sample extract (100 μL). The limits of detection (LODs) of aminoglycosides, beta-lactam, macrolide, and tetracyclines antibiotics were 60, 20–40, 60–80, and 40–60 μg/kg, respectively, which reached the requirements for the determination of antibiotic residue levels in the country and abroad. Consistent results were obtained in examining antibiotic residue in 60 animal-derived food samples using the microbial chromogenic assay and HPLC-MS/MS, indicating that the proposed assay could be used to detect antibiotic residues in animal-derived food samples with reliable results.