Emetic Bacillus cereus is one of the causative agents of foodborne diseases which can cause vomiting-type food poisoning after ingestion of contaminated food. To minimize B. cereus food poisoning, propidium monoazide (PMA) combined with quantitative polymerase chain reaction (qPCR) called PMA-qPCR was applied for detecting viable emetic B. cereus in milk. The cereulide synthetase gene of emetic B. cereus (cesB) was chosen for the primer, and PMA treatment was optimized at 3 μg/mL to inhibit the PCR amplification of DNA from dead cells. Under optimized assay parameters, the limit of detection (LOD) using this method were 102 CFU/mL in both pure culture and in spiked milk matrix. The cycle threshold (Ct) values obtained for this assay was not significantly affected by the presence of non-target bacteria such as E. coli O157:H7 which indicated the high selectivity of the assay for emetic B. cereus. The PMA-qPCR assay used in this study has the potential for sensitive detection of viable emetic B. cereus in milk.

中文翻译：

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通过PMA-qPCR分析法快速，定量检测乳汁中的催产性蜡状芽孢杆菌。

催产芽孢杆菌是食源性疾病的致病因素之一，食入污染的食物后可引起呕吐型食物中毒。为了最大程度地减少蜡状芽孢杆菌食物中毒，将单叠氮化丙锭（PMA）与定量聚合酶链反应（qPCR）称为PMA-qPCR的结合用于检测牛奶中的蜡状芽孢杆菌。选择催产芽孢杆菌的蜡状内酯合成酶基因（cesB）作为引物，并以3μg/ mL的浓度对PMA处理进行了优化，以抑制死细胞DNA的PCR扩增。在优化的测定参数下，使用这种方法在纯培养物和加标牛奶基质中的检出限（LOD）均为102 CFU / mL。非靶细菌（例如大肠杆菌O157）的存在不会显着影响通过此测定法获得的循环阈值（Ct）值：H7表明对催产芽孢杆菌的测定具有很高的选择性。这项研究中使用的PMA-qPCR分析具有潜在检测牛奶中蜡样芽孢杆菌的潜力。