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Bacterial infection is a global burden that results in numerous hospital visits and deaths annually. The rise of multi-drug resistant bacteria has dramatically increased this burden. Therefore, there is a clinical need to detect and identify bacteria rapidly and accurately in their native state or a culture-free environment. Current diagnostic techniques lack speed and effectiveness in detecting bacteria that are culture-negative, as well as options for in vivo detection. The optical detection of bacteria offers the potential to overcome these obstacles by providing various platforms that can detect bacteria rapidly, with minimum sample preparation, and, in some cases, culture-free directly from patient fluids or even in vivo. These modalities include infrared, Raman, and fluorescence spectroscopy, along with optical coherence tomography, interference, polarization, and laser speckle. However, these techniques are not without their own set of limitations. This review summarizes the strengths and weaknesses of utilizing each of these optical tools for rapid bacteria detection and identification. [ABSTRACT FROM AUTHOR]

A novel, green fluorescent β-alanylstyrylcoumarin derivative was synthesized and evaluated for its performance as a fluorogenic enzyme substrate on a range of clinically relevant microorganisms. The substrate was selectively hydrolysed by β-alanyl aminopeptidase producing P. aeruginosa resulting in an on-to-off fluorescent signal. Growth inhibitory effect of the substrate was observed on Gram positive bacteria and yeasts. Meanwhile, Gram negative species, despite their extremely protective cell envelope, showed ready uptake and accumulation of the substrate within their healthy growing colonies displaying intense green fluorescence. [ABSTRACT FROM AUTHOR]

New fluorogenic enzyme substrates were synthesized by the coupling of aminonaphthalenesulfonamides or 6-hydrazinobenz[ de ]isoquinoline-1,3-diones with β-alanine. The 6-hydrazinobenz[ de ]isoquinoline-1,3-diones were also condensed with a range of aryl aldehydes to give the corresponding hydrazones. The photophysical properties of the synthesized amines and hydrazines and their amide, hydrazide and hydrazone derivatives, were examined and they were also incorporated into Columbia agar in order to determine their potential for the detection of pathogenic bacteria. [ABSTRACT FROM AUTHOR]