电阻抗法检测食品中沙门氏菌

Study on rapid Conductance Detection of Salmonellas in Foods

介绍电阻抗法快速检测食品中沙门氏菌方法,通过对沙门氏菌选择培养基四硫磺酸盐煌绿增菌培养基(TTB)的改进,加入氧化三甲氨以增加培养基的电阻抗变化灵敏度,连续检测沙门氏菌代谢所引起培养基的电阻抗变化值,通过培养机电阻抗降低的百分比判定沙门氏菌的存在。经与常规培养法进行比较,对加入食品中的21种已知沙门氏菌属的检测,电阻抗法19个为阳性,检出率在90%以上,常规法检出18个,检测结果与常规培养法相一致,对于阴性结果能在48h内出具结果。结果表明电阻抗法能够快速、可靠地检测食品中的沙门氏菌。

A conductance method was proposed for the rapid detection of salmonellae in food, by adding trimethylamine- N- oxide to increase the conductance changes of the selective media Tetrathionate Broth(TTB), continuously monitored the conductance changes of the media caused by bacterial metabolism, judge the salmonellae Presence by the changes expressed as percentage decrease of the initial values.In comparing the conductance method with the standard culture method, the conductance method could result in 19 positive of 21 known samples with, recovery over 90% ; where as the standard culture method resulted only in 18 of 21, The testing result of the two methods are consistent.For negative investigation the results could be obtained within 48 h.It showed that the conductance method was very suitable as a screening method for salmonellae defection in foods and unique to its rapidess and reliablity.