FRET probe-based antibacterial susceptibility testing (F-AST) by detection of bacterial nucleases released by antibiotic-induced lysis

Abstract

This study demonstrates a novel and rapid antibacterial susceptibility testing (AST) method, called fluorescence resonance energy transfer (FRET) probe-based AST (F-AST), which relies on a nuclease-activated FRET probe that detects bacterial nucleases released by antibiotic-induced bacterial lysis. Three quality control (QC) strains and two additional clinically important strains were tested, and the minimum inhibitory concentration (MIC) values from both gold standard AST method (broth microdilution (BMD)) and the new F-AST method were compared. The resulting fluorescence signals from the F-AST method were obtained within 3-6 h and were consistent with MIC values obtained from the BMD method, which took more than 16 h. Thus, the F-AST method is a simple and rapid tool to detect antibacterial susceptibility, including MIC values, and provides a basis for rapid clinical treatments.

Keywords: Antibacterial susceptibility testing (AST); Bacterial nuclease; Fluorescence resonance energy transfer (FRET); Minimum inhibitory concentration (MIC).