Label-Free Electrochemical Microfluidic Chip for the Antimicrobial Susceptibility Testing

Area of Science:

• Biomedical Engineering
• Clinical Diagnostics
• Microfluidics

Background:

• Antibiotic resistance is a critical global health threat.
• Current antibiotic susceptibility testing (AST) methods are often slow, complex, and costly.
• There is a need for rapid, automated, and user-friendly AST solutions.

Purpose of the Study:

• To develop an automated electrochemical microfluidic chip (EMC) for simple and rapid AST.
• To enable faster bacterial count and minimum inhibitory concentration (MIC) determination.
• To reduce the time and resources required for AST.

Main Methods:

• Design and fabrication of a microfluidic chip with integrated gold microelectrodes.
• Automation of antibiotic mixing and distribution within microfluidic chambers.
• Electrical signal measurements for bacterial detection and AST.
• Comparison with conventional broth microdilution and AlamarBlue assays.

Main Results:

• The EMC achieved rapid bacterial count in 170 minutes and AST in 150 minutes.
• Testing time was significantly reduced compared to conventional broth microdilution (450 min for count, 240 min for AST).
• Accurate MIC evaluation was demonstrated on the EMC, comparable to established methods.
• The chip showed sensitivity, minimal antibiotic loss, and potential for reducing resistance evolution.

Conclusions:

• An automated, label-free, economical, and rapid EMC for AST has been successfully developed.
• The EMC offers a user-friendly and robust platform for evaluating AST, particularly in urine samples.
• This technology has the potential to improve patient treatment and control the spread of antibiotic resistance.