Abstract
Rapid detection of bacterial antibiotic resistance is paramount in clinical settings to enable timely and effective therapeutic interventions. Traditional approaches such as disc diffusion and broth dilution are indeed dependable, however, they suffer from a notable drawback of long assay durations. This is attributed to the inherent delay caused by bacteria's macroscopic growth rate, which often necessitates measurement periods exceeding 20 hours, a timeframe incompatible with the clinical urgency. In this study, we demonstrate a comprehensive strategy on rapid bacterial antimicrobial resistance profiling and testing in clinical samples via a label-free impedance-accelerated single-bacterium screening. This system involves one newly developed parameter that is calculated from the two-dimensional kernel density values of different density regions in bacterial impedance spectra. By evaluating the changes in bacterial populations over a certain period using this new parameter, antimicrobial resistance of individual strains of bacteria can be determined within 20-minute antibiotics exposure. This high-throughput method rapidly and accurately determines the resistance profiles of five clinical Enterobacteriaceae strains against six antibiotic types. During the analysis of the impedance spectrum, we have also observed that antibiotics with different antimicrobial mechanisms have distinct effects on the bacterial impedance profile. This proposed method demonstrates excellent accuracy and rapid response time, providing a novel and practical strategy for next-generation antimicrobial susceptibility testing (AST) and antibiotic management.