Sensitive and Selective Detection of Enterococcus faecalis Using a New Turn‐on Fluorogenic β‐glucosidase Substrate Combined with a Modified Selective Broth. (4th July 2022)

• Record Type: Journal Article
• Authors: Wei, Xianhu; Gu, Qihui; Feng, Ying; Zhang, Youxiong; Li, Ying; Zhang, Shuhong; Zhang, Jumei; Wu, Shi; Yang, Xiaojuan; Ye, Qinghua; Ding, Yu; Wang, Juan; Chen, Moutong; Wu, Qingping
• Is Part Of: Photochemistry and photobiology. Volume 99:Number 1(2023)
• Page Start: 68
• Page End: 77
• Publication Date: 2022-07-04
• Subjects: Photochemistry -- Periodicals; Light -- Physiological effect -- Periodicals; 541.35
• DOI: 10.1111/php.13662
• Languages: English
• ISSNs: 0031-8655

Abstract

Abstract: A new, simple‐to‐synthesize and sensitive turn‐on fluorogenic substrate (CFMU‐Glu ) for β‐glucosidase activity was developed. This probe was based on a 7‐hydroxycoumarin derivative (CFMU ) that could emit green fluorescence and had the low p K a value of 5.61 ± 0.01. CFMU‐Glu could be used for sensitive monitoring of the almond βGLU and Enterococcus faecalis ( E. faecalis ) at the optimal pHs of 6.50 and 7.00, respectively. Moreover, a new sensitive and selective fluorogenic broth (PBF‐B) for E. faecalis, utilizing CFMU‐Glu and polymyxin B, was also developed. Polymyxin B was discovered to can significantly improve the detection selectivity and signal intensity. The proposed 4‐four method using PBF‐B and a microcentrifuge tube could provide fluorogenic detection limits of 5.01 × 10 4 and 1.0 × 10 5 CFU mL −1 by fluorescence microplate reader and naked eye, respectively; it could also provide a turn‐on chromogenic detection limit of 1.0 × 10 6 CFU mL −1 by naked eye. The proposed method could detect 8 CFU mL −1 of E. faecalis in drinking water, Liangcha (herbal tea) and milk samples within 10 h, without pre‐enrichment. Abstract : A new, simple‐to‐synthesize and sensitive turn‐on fluorogenic substrate (CFMU‐Glu ) for β‐glucosidase activity was developed, which based on a 7‐hydroxycoumarin derivative (CFMU ) that could emit green fluorescence and had the low p K a value of 5.61 ± 0.01. CFMU‐Glu was successfully used for sensitive and selective fluorogenic and chromogenic detection of Enterococcus faecalis at the optimal pH of 7.00 by combing with a modified selective broth containing polymyxin B. Polymyxin B could significantly improve the detection selectivity and signal intensity.