Multiplex real-time PCR coupled with sodium dodecyl sulphate and propidium monoazide for the simultaneous detection of viable Listeria monocytogenes, Cronobacter sakazakii, Staphylococcus aureus and Salmonella spp. in milk. (September 2020)

• Record Type: Journal Article
• Authors: Qin, Hong; Shi, Xiuquan; Yu, Liang; Li, Ke; Wang, Jianwu; Chen, Jihua; Yang, Fei; Xu, Haiyan; Xu, Huilan
• Is Part Of: International dairy journal. Volume 108(2020)
• Publication Date: 2020-09
• Subjects: Dairying -- Periodicals; Industrie laitière -- Périodiques; Electronic journals; 338.1762142
• DOI: 10.1016/j.idairyj.2020.104739
• Languages: English
• ISSNs: 0958-6946

Abstract

Abstract: A sodium dodecyl sulphate (SDS)-propidium monoazide (PMA)-multiplex real-time PCR (mRT-PCR) assay for accurate and rapid detection of viable Listeria monocytogenes, Cronobacter sakazakii, Staphylococcus aureus and Salmonella spp. was established. The SDS and PMA pretreatments were used to eliminate the false-positive results caused by dead cells in mRT-PCR, in which the SDS could improve the membrane permeability of dead cells to PMA without affecting viable cells. Optimisation studies indicated that SDS and PMA at 100 μg mL −1 and 40 μm, respectively, were the most appropriate. Using the optimised parameters, the detection limit of SDS-PMA-mRT-PCR for L. monocytogenes, C. sakazakii, S. aureus and Salmonella spp. in spiked milk was 10 2 cfu mL −1, and the total assay time took less than 7 h. In conclusion, the SDS-PMA-mRT-PCR method developed in this study can accurately and quickly detect the combined contamination of viable L. monocytogenes, C. sakazakii, S. aureus and Salmonella spp. in milk.