Cabral Aaron D, Rafiei Nafiseh, de Araujo Elvin D, Radu Tudor B, Toutah Krimo, Nino Daniel, Murcar-Evans Bronte I, Milstein Joshua N, Kraskouskaya Dziyana, Gunning Patrick T
Department of Chemical & Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
ACS Sens. 2020 Sep 25;5(9):2753-2762. doi: 10.1021/acssensors.9b02490. Epub 2020 Aug 6.
Antibiotic resistance is a major problem for world health, triggered by the unnecessary usage of broad-spectrum antibiotics on purportedly infected patients. Current clinical standards require lengthy protocols for the detection of bacterial species in sterile physiological fluids. In this work, a class of small-molecule fluorescent chemosensors termed was shown to be capable of rapid, sensitive, and facile detection of broad-spectrum bacteria. The sensors act via a turn-on fluorescent excimer mechanism, where close-proximity binding of multiple sensor units amplifies a red shift emission signal. sensors were able to detect down to 10 CFUs of model strains by flow cytometry assays and showed selectivity over mammalian cells in a bacterial coculture through fluorescence microscopy. The studies reveal that the zinc(II)-chelates cyclen and cyclam are novel and effective binding units for the detection of both Gram-negative and Gram-positive bacterial strains. Mode of action studies revealed that the chemosensors detect Gram-negative and Gram-positive strains with two distinct mechanisms. Preliminary studies applying sensors to sterile physiological fluids (cerebrospinal fluid) in flow cytometry assays were successful. The results suggest that sensors can be developed as a rapid, inexpensive, and robust tool for the "yes-no" detection of broad-spectrum bacteria in sterile fluids.
抗生素耐药性是全球健康面临的一个重大问题，这是由对疑似感染患者不必要地使用广谱抗生素引发的。当前的临床标准要求采用冗长的方案来检测无菌生理体液中的细菌种类。在这项工作中，一类被称为 的小分子荧光化学传感器被证明能够快速、灵敏且简便地检测广谱细菌。这些传感器通过开启荧光准分子机制起作用，多个传感器单元的紧密结合会放大红移发射信号。通过流式细胞术检测， 传感器能够检测到低至10个菌落形成单位（CFU）的模型菌株，并且通过荧光显微镜观察，在细菌共培养中对哺乳动物细胞表现出选择性。研究表明，锌（II）螯合物环胺和环戊二胺是检测革兰氏阴性菌和革兰氏阳性菌菌株的新型有效结合单元。作用方式研究表明，化学传感器通过两种不同机制检测革兰氏阴性菌和革兰氏阳性菌菌株。将 传感器应用于流式细胞术检测无菌生理体液（脑脊液）的初步研究取得了成功。结果表明， 传感器可被开发成为一种用于在无菌液体中对广谱细菌进行“是与否”检测的快速、廉价且强大的工具。
