Porcellato Davide, Narvhus Judith, Skeie Siv Borghild
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Science, P.O. Box 5003, N-1432 Ås, Norway.
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Science, P.O. Box 5003, N-1432 Ås, Norway.
J Microbiol Methods. 2016 Aug;127:1-6. doi: 10.1016/j.mimet.2016.05.012. Epub 2016 May 17.
Droplet digital PCR (ddPCR) is one of the newest and most promising methods for the detection and quantification of molecular targets by PCR. Here, we optimized and used a new ddPCR assay for the detection and quantification of the Bacillus cereus group in milk. We also compared the ddPCR to a standard qPCR assay. The new ddPCR assay showed a similar coefficient of determination and a better limit of detection compared to the qPCR assay during quantification of the target molecules in the samples. However, the ddPCR assay has a limitation during quantification of a high number of target molecules. This new assay was then tested for the quantification of the B. cereus group in 90 milk samples obtained over three months from two different dairies and the milk was stored at different temperatures before sampling. The ddPCR assay showed good agreement with the qPCR assay for the quantification of the B. cereus group in milk, and due to its lower detection limit more samples were detected as positive. The new ddPCR assay is a promising method for the quantification of target bacteria in low concentration in milk.
液滴数字PCR（ddPCR）是通过PCR检测和定量分子靶标的最新且最具前景的方法之一。在此，我们优化并使用了一种新的ddPCR检测方法来检测和定量牛奶中的蜡样芽孢杆菌群。我们还将ddPCR与标准定量PCR（qPCR）检测方法进行了比较。在对样品中的靶分子进行定量时，新的ddPCR检测方法与qPCR检测方法相比，具有相似的决定系数和更好的检测限。然而，在对大量靶分子进行定量时，ddPCR检测方法存在局限性。然后，使用这种新检测方法对从两个不同乳品厂在三个月内采集的90份牛奶样品中的蜡样芽孢杆菌群进行定量，并且在采样前将牛奶保存在不同温度下。对于牛奶中蜡样芽孢杆菌群的定量，ddPCR检测方法与qPCR检测方法显示出良好的一致性，并且由于其较低的检测限，更多样品被检测为阳性。新的ddPCR检测方法是一种用于定量牛奶中低浓度靶细菌的有前景的方法。
