A team of researchers at the Indian Institute of Science (IISc) has developed a novel method to break down ‘biofilm barriers,’ enhancing the effectiveness of drugs against disease-causing bacteria.   The IISc team explained that many harmful bacteria, such as Klebsiella pneumoniae (K. pneumoniae), form protective biofilms – tough, matrix-like layers made of sugars, proteins, fats, and DNA. These biofilms act as formidable barriers that prevent antibiotics from reaching the bacteria, contributing to antibiotic resistance. To overcome this, the IISc researchers turned to an enzyme found in the digestive tract of cows.

K. pneumoniae, a bacterium commonly found in hospital settings, causes serious infections like pneumonia, urinary tract infections, and meningitis, often complicating conditions for diabetics and sometimes leading to limb amputations. The bacteria form a biofilm composed largely of polysaccharides, which are strings of sugar molecules that strengthen the biofilm and protect the bacteria from treatment.  To break down this biofilm, the IISc team focused on using enzymes that degrade polysaccharides. They identified that the bovine gut, which digests complex polysaccharides like cellulose and hemicellulose, could provide the right enzymes for this task. Specifically, they looked for glycoside hydrolases (GH), enzymes that break down polysaccharides, and found a promising candidate called GH-B2, located in the cow’s rumen (the largest stomach compartment).  

After synthesising GH-B2 in the lab, the team tested it on four different strains of K. pneumoniae isolated from hospital patients. They were surprised to find that GH-B2 was effective in breaking down the biofilm of all four strains, despite their varying serotypes.  

Debasis Das, Assistant Professor- Department of Inorganic and Physical Chemistry, IISc and the corresponding author of the study, noted that the broad effectiveness of GH-B2 across different bacterial strains was an unexpected and promising outcome.  This breakthrough offers hope for more effective treatments against biofilm-forming bacteria, paving the way for novel drug delivery strategies in the fight against antibiotic resistance.

(The Hindu)