叠氮溴化丙锭对食品中单增李斯特氏菌检测结果的影响

Influence of propidium monoazide( PMA) on detection of Listeria monocytogenes in food

为研究叠氮溴化丙锭(PMA)在单增李斯特氏菌检测中的作用,利用实时荧光PCR方法检测不同浓度PMA处理的单增李斯特氏菌标准菌株CMCC 54004的死菌和活菌核酸的扩增情况。结果显示,1.0 mg/ml PMA能有效抑制单增李斯特氏菌死菌核酸的扩增。经过PMA处理后单增李斯特氏菌死菌与未经PMA处理的检测结果间差异极显著,而PMA处理后CMCC 54004活菌与未经PMA处理的检测结果间差异性不显著。通过对PMA处理的CMCC 54004死菌、活菌、不同比例死菌与活菌混合液以及其在不同食品基质下的检测结果的比较,进一步证实,1.0 mg/ml PMA在单增李斯特氏菌检测中能有效减少死菌核酸的影响,提高检测结果的可靠性。

In this study, real-time fluorescence PCR method was employed to detect the nucleic acid amplification of dead cells and living cells of Listeria monocytogenes standard strain CMCC 54004 treated with different concentrations of propidium monoazide（ PMA） . The results showed that 1. 0 mg/ml PMA could effectively inhibit nucleic acid amplifica-tion in dead bacteria. There was a significant difference between the test results of Listeria monocytogenes dead bacteria treated with PMA and without PMA, however, no obvious difference was seen after PMA treatment on CMCC 54004 living bacteria. Further researches on CMCC 54004 dead cells, living cells and proportionally mixed dead and liv-ing cells treated with PMA and PMA in the presence of food interference suggested that 1. 0 mg/ml PMA could effectively reduce the influence of dead bacteria nucleic acid in Listeria monocytogenes detection, leading to relia-ble test results.