An inventive and reasonably priced microfluidic device created by researchers at the Indian Institute of Technology Madras (IIT Madras) can quickly identify whether bacteria are antibiotic-resistant or susceptible.

One crucial technique for determining whether medicines will be effective against a particular infection is antimicrobial susceptibility testing, or AST. It assists medical professionals in selecting the appropriate course of action and preventing antibiotic abuse, which is a primary contributor to AMR.

This lab-on-chip system, called “ε-µD,” is based on screen-printed carbon electrodes placed in a basic microfluidic chip, in contrast to many contemporary methods that depend on expensive metals, intricate fabrication procedures, or highly qualified experts.

Because of this strategy, the gadget is not only affordable but also appropriate for use in smaller clinics and remote medical facilities. It has a three-hour turnaround time.

Patients in intensive care units who could be experiencing difficulties from bacterial infections could benefit greatly from the device. Prof. S Pushpavanam of the Department of Chemical Engineering at IIT Madras stated that this could save lives and assist physicians in prescribing the appropriate course of action.

One of the biggest issues confronting international healthcare systems at the moment is antimicrobial resistance (AMR). According to estimations, bacterial AMR was responsible for around 4.95 million deaths globally in 2019 and has been named one of the top 10 risks to global health by the World Health Organization (WHO).

Conventional AST techniques are labor-intensive and usually take 48 to 72 hours. They entail cultivating bacterial cultures and monitoring how they react to antibiotics. Broad-spectrum antibiotics may be used as a stopgap as a result of this delay, which makes the resistance issue worse.

In just three hours, the new, affordable phenotypic testing tool evaluates bacterial growth and drug susceptibility using electrochemical signals.

Gram-positive B. subtilis and gram-negative E. coli were the two bacterial species that the researchers tested the device on in the study, which was published in the journal Nature Scientific Reports.

To verify the device’s capacity to identify both types of responses, they employed two antibiotics with distinct mechanisms of action: tetracycline, which stops bacteria from developing, and ampicillin, which kills germs. Within three hours, the equipment was able to identify susceptibility profiles.

In order to demonstrate the device’s potential in clinical diagnostics, the scientists also tested it on urine samples that had been tainted with E. coli. They were able to detect tetracycline resistance.