Cow rumen enzymes show promise against stubborn infection biofilms: IISc study
Researchers at the Indian Institute of Science (IISc) have identified enzymes from a cow's digestive system that can break down the protective layers—called biofilms—formed by certain bacteria on wounds and medical surfaces. These biofilms are a major cause of persistent infections and delayed healing, particularly in healthcare settings.
The study focuses on Acinetobacter baumannii, a bacterium that poses a significant threat in hospitals. This pathogen frequently forms biofilms on wounds and medical equipment, making infections difficult to treat. Biofilms are communities of bacteria encased in a sticky matrix made of polysaccharides, proteins, lipids, and DNA. This physical barrier reduces the effectiveness of antibiotics and the body's immune response.
The IISc team used genomic data from microbes present in the bovine rumen—the largest compartment of a cow's stomach—to identify enzymes capable of digesting cellulose, a polysaccharide also abundant in the cow's diet. Since polysaccharides make up between 45% and 95% of bacterial biofilms, the researchers reasoned that enzymes breaking down cellulose might also degrade biofilm structures.
They found that a specific enzyme, named CRhAB (Cow rumen hydrolase against A. baumannii), was highly effective against biofilms of both A. baumannii and Klebsiella pneumoniae, another dangerous pathogen. The enzyme not only reduced biofilm formation but also suppressed the expression of genes critical for biofilm maintenance.
“Both A. baumannii and K. pneumoniae are among the most notorious of the ESKAPE pathogen group—a collection of antibiotic-resistant bacteria that are a major public health concern. This enzyme acts against both, offering a dual strategy with a single agent,” said Dipshikha Chakravortty, Professor in the Department of Microbiology and Cell Biology (MCB) at IISc and co-corresponding author of the study.
The research team also developed a specialized gauze impregnated with the enzyme to manage wound infections. In addition, they are working on a patch-like wound dressing for difficult-to-treat conditions such as diabetic foot infections. The researchers are also exploring delivery systems for respiratory infections, including those caused by K. pneumoniae, and the possibility of combining multiple enzymes to target a wider range of pathogenic biofilms.
“A long-term goal is to develop an inhalable or nebulisable formulation of CRhAB that delivers the enzyme directly to the lungs, preventing biofilm formation and disrupting established biofilms. Such a localised, non-invasive approach could offer a promising new treatment for chronic A. baumannii respiratory infections,” said Reshma Ramakrishnan, former PhD student in the Department of Inorganic and Physical Chemistry (IPC) and first author of the study.
The research, led by Debasis Das, Associate Professor at IPC, along with Chakravortty and colleagues, highlights the potential of natural enzymes as a novel strategy to combat biofilm-related infections. The findings could lead to new treatments that address the root cause of antibiotic resistance in persistent infections.
