A Visualized Isothermal Amplification Method for Rapid and Specific Detection of Emetic and Non-emetic Bacillus cereus in Dairy Products

• Published in: Frontiers in microbiology 2022-03, Vol.13, p.802656-802656
• Main Authors: Wang, Lei, Yang, Huansen, Wang, Kun, Yang, Haitao, Zhao, Mengdi, Shang, Yuping, Wang, Fang, Dong, Jingquan, Zhao, Weiguo, Li, Li, Liang, Wei, Wang, Yan
• Format: Article
• Language: English
• Subjects: Bacillus cereus; cereulide synthetase; gyrase B; lateral flow strip; Microbiology; recombinase polymerase amplification
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.802656

is widely distributed in foods, especially dairy products, and can lead to diarrhea (non-emetic ) and emesis (emetic ). Although diarrhea due to . is usually mild, emesis can lead to acute encephalopathy and even death. To develop rapid and sensitive detection methods for in foods, specific primers targeting the ( ) and cereulide synthetase ( ) genes were designed and screened using recombinase polymerase amplification (RPA). Probes and base substitutions were introduced to improve specificity and eliminate primer-dependent artifacts. The 5' ends of the reverse primers and probes were modified with biotin and fluorescein isothiocyanate for detection of RPA products on a lateral flow strip (LFS). The developed RPA-LFS assay allows detection within 20 min at 37°C with no cross-reactivity with other foodborne pathogens. The limit of detection was 10 copies/ml and 10 CFU/ml in pure cultures and milk, respectively. Comparisons with established methods using cream obtained similar results. A specific, rapid, and sensitive RPA-LFS assay was successfully developed for on-site detection of in dairy products to distinguish emetic from non-emetic strains.