免疫富集联合基质辅助激光解吸电离飞行时间质谱法测定牛奶、鸡蛋中的沙门氏菌

Determination of Salmonella in milk and eggs by immune enrichment and matrix-assisted laser desorption ionization time-of-flight mass spectrometry

中文关键词:  免疫磁珠  基质辅助激光解吸电离飞行时间质谱法  沙门氏菌  鉴定

英文关键词:immunomagnetic beads  matrix-assisted laser desorption/ ionization time of flight mass spectrometry  Salmonella  identification

中文摘要:

      目的 建立免疫富集联合基质辅助激光解吸电离飞行时间质谱法(matrix-assisted laser desorption/ ionization time of flight mass spectrometry, MALDI-TOF MS)检测牛奶、鸡蛋中沙门氏菌的方法。方法 沙门氏菌经免疫磁珠特异性富集后采用MALDI-TOF MS鉴定, 并优化富集过程中的抗体、免疫磁珠添加量以及捕获时间, 研究其特异性, 并用于实际样品中沙门氏菌的检测。结果 富集过程最佳反应条件为: 每1 mg磁珠中抗体添加量为250 μg, 1 mL菌样中免疫磁珠添加量为600 μL, 捕获时间为30 min, 免疫磁珠捕获沙门氏菌具有特异性; 用于检测牛奶和鸡蛋中的沙门氏菌时, 将浓度为3 CFU/mL的沙门氏菌特异性富集后选择性增菌9 h即可被MALDI-TOF MS准确鉴定。结论 该方法具有选择性好, 特异性高, 耗时短, 结果准确的优点, 为食品中沙门氏菌的检测提供相关参考。

英文摘要:

      Objective To establish a method for the detection of Salmonella in milk and eggs by immune enrichment combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Methods Salmonella was specifically enriched by immunomagnetic beads and identified by MALDI-TOF MS, and the addition of antibodies, immunomagnetic beads and capture time in the enrichment process were optimized to study its specificity and use it for the detection of Salmonella in actual samples. Results The optimal reaction conditions for the enrichment process were: the antibody addition amount in 1 mg magnetic bead was 250 μg, the immunomagnetic bead addition amount in 1 mL of bacteria was 600 μL, the capture time was 30 min, immuno-magnetic beads had specificity for capturing of Salmonella. When it was used to detect Salmonella in milk and eggs, the Salmonella with a concentration of 3 CFU/mL can be selectively enriched for 9 h by MALDI-TOF MS accurate identification. Conclusion The method has the advantages of good selectivity, high specificity, short time consumption and accurate results, and provides relevant references for the detection of Salmonella in food.