Anti-biofilm and Quorum Sensing Inhibitory Potential of Acanthus ilicifolius against Uropathogens

This study investigates the anti-biofilm activity of Acanthus ilicifolius leaf crude extract against uropathogens. Biofilm inhibitory concentration (BIC) was found to be at 75 μg/ml for Pseudomonas aeruginosa and 125 μg/ml for Escherichia coli and Klebsiella pneumoniae. The A. ilicifolius crude extract anti-biofilm efficacy was validated through light microscope, the A. ilicifolius crude extract significantly reduced the biofilm formation. The anti-adherence efficacy of crude extract was confirmed through confocal laser scanning microscope, the crude extract coated surface layer significantly reduced the biofilm adherence. The A. ilicifolius crude extract also inhibited the exopolysaccharide production and affect the mature biofilm architecture. In addition, A. ilicifolius extract also showed a promising anti-quorum sensing potential against C. violaceum. About 1mg/ml of the A. ilicifolius crude extract inhibited the violacein pigment production. Minimum inhibitory concentration (MIC) was found to be at 180μg/ml for P. aeruginosa, 220 μg/ml for E. coli and 200 μg/ml for K. pneumoniae showed very mild bacterial inhibition and growth curve assay showed no significant difference among with control and treated samples. The obtained results are clearly to indicate the A. ilicifolius crude extract as an ideal anti-biofilm agent against uropathogens.