New Delhi, Aug 25 : Researchers at the Indian Institute of Technology Madras (IIT Madras) have developed an innovative and affordable microfluidic device that can rapidly determine whether bacteria are resistant or susceptible to antibiotics.

Antimicrobial Susceptibility Testing (AST) is an important method used to identify which antibiotics will work against a specific infection. It helps doctors choose the right treatment and avoid the misuse of antibiotics, which is a major cause of AMR.

Unlike many modern techniques that rely on costly metals, complex fabrication processes, or require highly skilled technicians, this lab-on-chip device, known as 'ε-µD', is based on screen-printed carbon electrodes embedded in a simple microfluidic chip.

This approach makes the device not only economical but also suitable for deployment in smaller clinics and rural healthcare centres. It can deliver results within three hours.

'The device can make a real impact on patients in Intensive Care Units, who may be suffering from complications due to bacterial infections. This will help the doctors prescribe the right treatment and can be life-saving,' said Prof. S Pushpavanam, from the Department of Chemical Engineering, IIT Madras.

Antimicrobial resistance (AMR) is one of the most pressing challenges facing global healthcare systems today. The World Health Organization (WHO) has identified AMR as one of the top 10 threats to global health, and estimates suggest that nearly 4.95 million deaths worldwide in 2019 were associated with bacterial AMR.

Traditional AST methods involve growing bacterial cultures and observing their response to antibiotics, and are labour-intensive, typically taking 48 to 72 hours. This delay can lead to the use of broad-spectrum antibiotics as a stopgap, which in turn exacerbates the resistance problem.

The new cost-effective phenotypic testing device uses electrochemical signals to assess bacterial growth and antibiotic susceptibility in just three hours.

In the study, published in the Nature Scientific Reports journal, the researchers tested the device on two types of bacteria -- gram-negative E. coli and gram-positive B. subtilis.

They used two antibiotics with different modes of action -- ampicillin, which kills bacteria, and tetracycline, which prevents them from growing -- to confirm the device's ability to detect both kinds of responses. The device was able to detect susceptibility profiles within three hours.

The team also tested the device on urine samples spiked with E. coli and successfully identified resistance to tetracycline -- showing the potential of this device in clinical diagnostics.

/IANS