IISc scientists discover cow enzyme effective against drug-resistant bacteria

In a recent scientific breakthrough, scientists at IISc Bengaluru have discovered that an enzyme found in the digestive system of cows can be effective against ‘biofilms’ that are formed by multiple species of drug-resistant bacteria.

The research team, comprising IISc scientists Debasis Das, Reshma Ramakrishnan, Kirti Parmar, Dipshikha Chakravortty, Debmitra Sen, Velpandi Ramachandran and Raju S Rajmani, published their findings in the journal Nature.

This comes almost two years after a similar discovery at IISc in November 2024, where another cow enzyme was also found to have an effect on ‘biofilms’ formed by drug-resistant bacteria. These biofilms protect the bacteria against antibiotics as well as the immune system.

The enzyme that IISc tested in 2024 was found to be able to break down these polysaccharides and make the bacteria vulnerable to antibiotics and other treatments. This year, the IISc researchers isolated an enzyme known as CRhAB, which is effective not only at breaking the biofilms of the original bacterium, K pneumoniae, but also another bacterium, known as Acinetobacter baumannii.

According to a statement from IISc, A baumannii is also a problem in healthcare situations, as it causes infections and delayed healing by readily infecting wounds and medical surfaces. It is also one of the microbes that have displayed increased drug resistance.

These microbes are among the ESKAPE pathogen group, a set of bacteria that are known for causing drug-resistant infections in hospitals. Researchers tested the new enzyme on mice with infected wounds using a gauze dressing containing the enzyme.

Professor Dipshikha Chakravortty of the Department of Microbiology said, “Maintaining the enzyme-immobilised gauze over the wound throughout the study was particularly difficult because the mice naturally tried to remove the dressing.

We had to optimise the experimental setup to ensure that the gauze remained in place while minimising stress.” The research team is also working on creating a wound dressing that could be applied to diabetic foot infections, and potentially creating a way for the new enzyme to be inhaled to deal with respiratory infections.