Press release written by Dr. Swapnil Ganesh Sanmukh.
Biofilms are bacterial consortia that are residing on various surfaces, embedded in the extracellular polymeric substances that they have secreted. Biofilms form a protective layer for the resident bacteria, shielding them from antibiotics, disinfectants, and environmental stress. Biofilms physically protect persister cells from the immune system and allow them to survive high antibiotic concentrations, leading to therapeutic failure with conventional antibiotics. They are present in about 80% of bacterial infections. Because they are less susceptible to antibiotics than plankton bacteria, biofilms pose a significant challenge in the treatment of chronic infections. Most biofilm-forming bacteria, including Escherichia coli (E. coli), exhibit drug resistance through biofilm-mediated mechanisms. Over 80% of community-acquired urinary tract infections, which affect 150 million people globally annually, are caused by uropathogenic E. coli (UPEC). The formation of structures resembling intracellular biofilms has been linked to the increased survival of UPEC in urinary tract infections.
Bacteriophages and their different lytic enzymes have been reported for effective antibacterial as well as anti-biofilm therapies but more focus has been provided to the lytic phages due to the specificity of phages towards their bacterial host through single phage or cocktails with or without antibiotic combinations. Also, endolysins and de-polymerases have been explored for antibacterial and antibiofilm activities both in-vitro and in-vivo.
Our reported studies focus on the broad host specificity of phages and phages as natural enzyme-linked nanoparticles. To prove this, we selected the phages exhibiting depolymerase activity through plaque morphology and studied the effect of specific and non-specific phages on in-vitro biofilm removal as well as the in-vivo survival of Galleria melonella larvae. Our work demonstrated that bacteriophages showing depolymerase activity irrespective of their specificity can be effective in biofilm removal and thereby improve the survival of Galleria melonella larvae infected with various E. coli strains. These positive effects were further enhanced when the phages were administered in combination with antibiotics.
Further research is necessary to fully understand the potential of such bacteriophage-bound depolymerase activity and their applications to demonstrate their potential as natural enzyme-bound nanoparticles.