Toward Decentralizing Antibiotic Susceptibility Testing via Ready-to-Use Microwell Array and Resazurin-Aided Colorimetric Readout

Abstract

Supporting InformationThe Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.analchem.0c04095. Experimental section: Chip design and fabrication, preparation of ready-to-use microwell array with preloaded antibiotics, preparation of bacteria samples, data analysis of marcAST result, evaluation of rehydration process of the microwell array device, and clinical isolate testing. Figures: Microwell device structure, demonstration of operation procedure with a 30 s step prior to AST, time course of marcAST with ciprofloxacin and E. coli ATCC 25922, MIC determination using benchtop in-tube broth dilution method, ready-to-use microwell array device shelf life, MIC determination of S. aureus ATCC 23922 with gentamicin, and classification of antimicrobial susceptibilities for additional clinical isolates. Tables: Interpretive categories and MIC breakpoints of four antibiotics for Enterobacteriaceae species based CLSI guidelines, and AST profiles of clinical isolates (n = 7).

An antibiotic concentration gradient microfluidic device integrating surface-enhanced Raman spectroscopy for multiplex antimicrobial susceptibility testing

“…Although a microchamber can increase the number of sensing spots and reduce the required sample volume and assay time, it is a challenge to simultaneously generate multiple antibiotic concentrations for MIC determination in a single chip. The first method involves fabricating a series of parallel microchannels and introducing different antibiotic concentrations through different inlets 14,15 or the same antibiotic concentration into different microchamber sizes. 16 Another method is based on the laminar flow behavior of microfluidics.…”

Direct microfluidic antibiotic resistance testing in urine with smartphone capture: significant variation in sample matrix interference between individual human urine samples

“…Microuidic device design varies considerably, so test volumes vary from picolitres to mL. 7,11,17 However, for microdevices having test volumes below 1 mL, high dilution is likely to compromise utility for clinical UTI samples. The distribution of bacteria in microuidic devices is oen dictated by Poisson statistics.…”

Advances in Antimicrobial Resistance Monitoring Using Sensors and Biosensors: A Review

“…Colorimetric sensors offer a number of advantages including: simple procedure, low cost, and the possibility of observing color changes with the naked eye or with simple instrumentation in the case of quantitative analysis [70,118]. The use of chemical species that changes color with respect to bacterial growth, such as Resazurin [19,119], or the use of enzymes, such as Horseradish Peroxidase (HRP), that modifies substrates according to the number of microbial cells, can help to measure susceptibility in real-time [70].…”