An antibiotic concentration gradient microfluidic device integrating surface-enhanced Raman spectroscopy for multiplex antimicrobial susceptibility testing
Journal
Lab on a chip
Journal Volume
22
Journal Issue
9
Pages
1805-1814
Date Issued
2022
Author(s)
Abstract
Antimicrobial susceptibility testing (AST) is a key measure in clinical microbiology laboratories to enable appropriate antimicrobial administration. During an AST, the determination of the minimum inhibitory concentration (MIC) is an important step in which the bacterial responses to an antibiotic at a series of concentrations obtained in separate bacterial growth chambers or sites are compared. However, the preparation of different antibiotic concentrations is time-consuming and labor-intensive. In this paper, we present a microfluidic device that generates a concentration gradient for antibiotics that is produced by diffusion in the laminar flow regime along a series of lateral microwells to encapsulate bacteria for antibiotic treatment. All the AST preparation steps (including bacterium loading, antibiotic concentration generation, buffer washing, and isolated bacterial growth with an antibiotic) can be performed in a single chip. The viable bacterial cells in each microwell after the antibiotic treatment are then quantified by their surface-enhanced Raman scattering (SERS) signals that are acquired after placing a uniform SERS-active substrate in contact with all the microwells. For proof-of-concept, we demonstrated the AST performance of this system on ampicillin (AMP)-susceptible and -resistant E. coli strains. Compared with the parameters for conventional AST methods, the AST procedure based on this chip requires only 20 μL of bacteria solution and 5 h of operation time. This result indicates that this integrated system can greatly shorten and simplify the tedious and labor-intensive procedures required for current standard AST methods.
SDGs
Other Subjects
Antibiotics; Escherichia coli; Laminar flow; Microfluidics; Raman scattering; Raman spectroscopy; Substrates; Surface scattering; Antibiotic concentration; Antibiotic treatment; Antimicrobial susceptibility testing; Bacterial growth; Concentration- gradients; Enhanced Raman scattering; Labour-intensive; Micro wells; Microfluidics devices; Surface enhanced Raman; Fluidic devices; antiinfective agent; bacterium; Escherichia coli; lab on a chip; microbial sensitivity test; microfluidics; procedures; Raman spectrometry; Anti-Bacterial Agents; Anti-Infective Agents; Bacteria; Escherichia coli; Lab-On-A-Chip Devices; Microbial Sensitivity Tests; Microfluidics; Spectrum Analysis, Raman
Publisher
ROYAL SOC CHEMISTRY
Type
journal article