STANDARDIZING METHODS TO EVALUATE THE EFFICACY OF ANTIBIOFILM AGENTS

Microbial biofilms are a major cause of hospital-acquired infections and play a critical role in the dissemination of antimicrobial resistance. Cells within biofilms exhibit altered physiology and resistance to antimicrobial agents, making biofilm associated infections challenging to treat. Although numerous compounds are being evaluated for antibiofilm activity, lack of standardized and optimized evaluation methods often result in poor reproducibility and inconsistent interpretation of efficacy. This study aimed to optimize in-vitro methods for assessing the efficacy of antibiofilm agents against clinically relevant biofilm forming bacteria. Biofilms of Klebsiella pneumoniae MTCC 432, Pseudomonas aeruginosa MTCC 2453, Staphylococcus aureus MTCC 3160 and Staphylococcus epidermidis MTCC 3615 were evaluated using model antibiofilm agents like acetic acid and sodium dodecyl sulphate. Assays for minimum biofilm inhibitory concentration (MBIC), minimum biofilm eradication concentration (MBEC), biofilm dispersion, viability of biofilm embedded cells, extracellular DNA (eDNA) release and exopolysaccharide production and emulsification were standardized. Species-specific differences in biofilm eradication and dispersion thresholds were observed signifying organism specific evaluation of the antibiofilm agents. The optimized methods exhibit enhanced reproducibility and revealed species specific differences in biofilm eradication and dispersion. These methods assure reliable evaluation of antibiofilm agents and increase the comparability of the agents.