【摘要】 为了解决PCR技术不能有效鉴别食品中细菌的死活状态,试验采用叠氮溴化丙锭(PMA)结合定量PCR技术建立食品中志贺菌的活菌检测方法。结果表明:样品中添加浓度为10~20μg/mL的PMA,经过3~5 min强光照射处理,使PMA与细胞膜受损细菌中的DNA共价交联,同时水解游离的PMA,在活菌比例大于1%时实现活菌的定量检测,避免假阳性结果。更多还原

【Abstract】 To resolve the problem that PCR assay cannot effectively discriminate between live and dead bacteria,a detection method for live Shigella was developed by propidium monoazide( PMA) combined with quantitative PCR technique. The results showed that the sample bacteria were added with 10 ~ 20 μg /mL of PMA,and were treated with strong illumination for 3 ~ 5 min to induce covalent cross- linking of PMA with the DNA from the bacteria with damaged cell membrane,while hydrolyzing free PMA. The quantitative detection for live bacteria in food could be achieved when the proportion of live bacteria was greater than 1%. The results indicate that the method of PMA combined with quantitative PCR avoids false- positive results.更多还原