【摘要】 目的探讨克罗诺杆菌TaqMan-MGB探针实时荧光PCR在婴幼儿奶粉食品安全监测中的应用效果。方法制备克罗诺杆菌染菌量为1.5×100~106CFU/25g奶粉的样品,在增菌48 h内每隔4 h各取1 ml提取DNA,进行TaqMan-MGB探针实时荧光PCR,并在婴幼儿奶粉食品安全风险监测中应用,同步进行细菌分离、TaqMan探针实时荧光PCR(美国FDA推荐),比较3种方法的敏感性和符合率。结果 3种方法可检测到1.5 CFU/25 g奶粉染菌量样本所需增菌培养的时间不一样,TaqMan-MGB探针实时荧光PCR需18 h,美国FDA推荐的TaqMan探针实时荧光PCR需24 h,分离培养则需要36 h。TaqMan-MGB探针实时荧光PCR从293份样本的前增菌液中检出15份阳性,从77个可疑菌落中检出23个阳性菌落,鉴定结果与另2种方法一致。结论克罗诺杆菌TaqMan-MGB探针实时荧光PCR快速、特异、灵敏,可用于婴幼儿奶粉筛查和辅助鉴定,提高食品安全风险监测的速度和灵敏度。更多还原

【Abstract】 Objective The aim of this study was to know about the application effect for rapid detection of Cronobacter spp.from infant milk powder in food safety risk monitoring by TaqMan- MGB probe based real- time PCR. Methods Seven gradient dilution for artificially inoculated samples containing final concentration of Cronobacter spp. from 1. 5 × 100 to 1. 5 × 106 CFU per 25 g milk powder were prepared,and nucleic acid was isolated for an interval of four hours in the 48 hour cultured time. TaqMan- MGB probe based real- time PCR was performed. Meanwhile,the traditional method and TaqMan probe based real- time PCR recommended by U. S. FDA were done to compare the detection limit and the coincidence rate in food safety risk monitoring. Results The cultured time to be detected for 1. 5 × 100 CFU per 25 g milk powder dilution by three methods were different. TaqMan- MGB probe based real- time PCR needed 18 hours,while TaqMan probe based real- time PCR recommended by U. S. FDA and traditional method needed 24 and 36 hours,respectively. TaqMan- MGB probe based real- time PCR checked 15 positive samples out of 293 samples,and identified 23 positive bacterial colony from 77 suspected colonyes,which were the same with another two methods. Conclusion The TaqMan- MGB probe based real- time PCR assay for Cronobacter spp. was rapid,specific and sensitive,and could be used in the screening and identification of Cronobacter spp.,improving the sensitivity and speed of food safety risk monitoring.更多还原