Will this antibiotic work for you? A quick and easy method of testing antimicrobial susceptibility

Antimicrobial resistance (AMR) directly causes an estimated 1.3 million deaths around the globe annually. A leading cause of AMR is the misuse and overuse of antibiotics, which has allowed microbes to mutate over time and develop insensitivity to the drugs designed to kill them, making infections harder to treat and increasing the risk of disease spread.

A key step to preventing AMR is to test the susceptibility of a microbe against certain antibiotics before prescribing them to a patient, which increases the likelihood of effective treatment. While current methods of evaluating AMR exist, they are incredibly slow with a turnaround time of over 20 hours. This emphasizes the need for a rapid method that evaluates antimicrobial susceptibility without sacrificing accuracy.

Associate Professor Ye Ai from the Singapore University of Technology and Design's (SUTD) Engineering Product Development and his team successfully developed an electrical impedance-based microfluidic platform that provides rapid and accurate AMR evaluation within an hour.

Currently, broth microdilution and disk diffusion are the gold standard for evaluating AMR. However, these culture-based methods rely heavily on manual work and subjective visual measurement of bacterial growth that require at least 18 to 24 hours of incubation.

To combat this, the research team developed a novel electrical impedance-based microfluidic platform that can perform rapid antimicrobial susceptibility testing (AST). It works by measuring the bacterial membrane permeability after antibiotic exposure.

"Because the change in membrane permeability of susceptible bacteria can be detected by the impedance-based AST as fast as 30 minutes after exposure to antibiotics, long-term bacterial culture is not required in our approach," explained Assoc Prof Ai.

Image source: SUTD.