Strategies of Detecting Bacteria Using Fluorescence-Based Dyes

Abstract

Identification of bacterial strains is critical for the theranostics of bacterial infections and the development of antibiotics. Many organic fluorescent probes have been developed to overcome the limitations of conventional detection methods. These probes can detect bacteria with “off-on” fluorescence change, which enables the real-time imaging and quantitative analysis of bacteria in vitro and in vivo. In this review, we outline recent advances in the development of fluorescence-based dyes capable of detecting bacteria. Detection strategies are described, including specific interactions with bacterial cell wall components, bacterial and intracellular enzyme reactions, and peptidoglycan synthesis reactions. These include theranostic probes that allow simultaneous bacterial detection and photodynamic antimicrobial effects. Some examples of other miscellaneous detections in bacteria have also been described. In addition, this review demonstrates the validation of these fluorescent probes using a variety of biological models such as gram-negative and -positive bacteria, antibiotic-resistant bacteria, infected cancer cells, tumor-bearing, and infected mice. Prospects for future research are outlined by presenting the importance of effective in vitro and in vivo detection of bacteria and development of antimicrobial agents.

Phenotyping of Methicillin-ResistantStaphylococcus aureusUsing a Ratiometric Sensor Array

“…Conventional methods for identifying bacterial genotypes include pulsed-field gel electrophoresis, multilocus sequence typing (MLST), spa typing, SCC mec typing, repetitive element palindromic PCR, and STAR gene restriction profile analysis . While the majority of these methods can decode the genomic information of a given bacterium, they require dedicated facilities, are labor-intensive, and require lysis of the bacterial cells to isolate nucleic acids prior to analysis . This limits their utility for MRSA strain identification in point-of-care analyses.…”

A computational two‐photon fluorescence approach for revealing label‐free the 3D image of viruses and bacteria

“…[3] A recent technical advance for detecting bacteria with fluorescence-based dyes has allowed to assess simultaneously their physiological states while targeting specific biomolecules and physiological processes. [3,4] But these solutions do not deliver a result in live or in situ and are often expensive, time-consuming, associated with complex preparation procedures, or can lead to false positive/negative results. Two-photon fluorescence lifetime imaging (FLIM) delivers images of microbial systems at micrometric scale.…”

“…Free viral particles-named virions-or bacteria constitute a set of biomedical objects of first interest in many medical or biological situations. Revealing their presence is a strategical concern for which several accurate solutions are routinely operated such as PCR (polymerase chain reaction) [1], conventional laboratory-based culture media, immunological techniques, flow cytometry [2], or Raman spectroscopy [3]. A recent technical advance for detecting bacteria with fluorescence-based dyes has allowed to assess simultaneously their physiological states while targeting specific biomolecules and physiological processes [3,4].…”

“…Revealing their presence is a strategical concern for which several accurate solutions are routinely operated such as PCR (polymerase chain reaction) [1], conventional laboratory-based culture media, immunological techniques, flow cytometry [2], or Raman spectroscopy [3]. A recent technical advance for detecting bacteria with fluorescence-based dyes has allowed to assess simultaneously their physiological states while targeting specific biomolecules and physiological processes [3,4]. But these solutions do not deliver a result in live or in situ and are often expensive, time-consuming, associated with complex preparation procedures, or can lead to false positive/ negative results.…”

Recent Progress in Identifying Bacteria with Fluorescent Probes

“…For example, nitroreductase (NTR) and alkaline phosphatase are widely expressed in both Gram-positive and Gram-negative bacteria. In addition, antibiotic-resistant pathogens express high levels of β -lactamase used to destroy antibiotics [ 7 , 8 , 9 ].…”