An elegant nitroreductase responsive fluorescent probe for selective detection of pathogenic Listeria in vitro and in vivo.

Abstract Listeria monocytogenes (Listeria) is a facultative pathogenic bacterium, and a sensitive method for specific detection of Listeria is considered of clinically significant. However, current approaches for identifying Listeria are time consuming or tentative, and especially, cannot identify bacterial viability and antibiotic efficacy, which are critical in establishing a treatment recipe. Herein, we have developed a nitroreductase (NTR) responsive fluorescent probe (NRFP) with a fluorescence off-on feature, which could rapidly detect Listeria in vitro and in vivo with high specificity and sensitivity. NRFP showed a selective response to NTRs over other biological reductants, and could detect NTRs as low as 12.5 ng/mL. Furthermore, NRFP responded rapidly to NTRs within 10 min, enabling it real-time monitoring NTR production. Most importantly, NRFP could not only distinguish Listeria from other bacteria in vitro and in vivo for the first time, but could provide valuable information about Listeria desired for healthcare professionals, such as the presence and viability. Particularly, NRFP could real-time monitor antimicrobial effects in vivo , thereby identifying effective antibiotics for Listeria infections. Overall, NRFP appears to be an ideal imaging probe for Listeria , and possesses great potentials in diagnostic and therapeutic applications. Graphical abstract fx1 Highlights • A novel nitroreductase responsive probe for identifying Listeria in vitro and in vivo. • Selective identification of Listeria based on NTR expression profiles in bacteria. • The probe provides valuable information about Listeria including the presence, viability and antibiotic efficacy. • A new strategy with a great potential in diagnosis and treatment of Listeria -related diseases. [ABSTRACT FROM AUTHOR]