prodigiosin and pyoverdin

The emerging prevalence of multidrug-resistance in Gram-negative pathogens, due to conventional antimicrobial therapeutics, has led the researchers to emphasize on development of alternative novel strategies to suppress the bacterial virulence and pathogenicity through inhibition of quorum sensing (QS) and biofilms. QS is a bacterial communication system to produce density-dependent response via chemical signalling that controls pathogenesis and biofilms formation. Leaves of green tea are used worldwide as beverage which is also known for its broad-spectrum therapeutic efficacy. In this work, we have identified and characterized the most bioactive faction of green tea extract and evaluated the anti-QS and antibiofilm activity of green tea ethyl acetate fraction (GTEF) i.e. most active fraction, on three different Gram-negative bacterial pathogens. GTEF inhibited the violacein production by >75% in C. violaceum 12472. Many virulence factors of P. aeruginosa PAO1 viz. pyocyanin, pyoverdin, exoprotease, elastase, rhamnolipid production, and swimming motility were remarkably reduced in presence of sub-MICs of GTEF. Moreover, prodigiosin, protease activity, cell surface hydrophobicity, and swimming of S. marcescens MTCC 97 were also decreased significantly by the supplementation of GTEF in culture media. GTEF exhibited broad-spectrum antibiofilm action with >80% reduction in biofilm formation of test pathogens. In silico studies gave a mechanistic insight of action of GTEF. Molecular modelling revealed that phytoconstituents detected by GC/MS exhibited affinity (in order of 10

Topics: Anti-Bacterial Agents; Bacterial Proteins; Biofilms; Dose-Response Relationship, Drug; Exopeptidases; Glycolipids; Gram-Negative Bacteria; Hydrophobic and Hydrophilic Interactions; Indoles; Microbial Sensitivity Tests; Models, Molecular; Molecular Docking Simulation; Oligopeptides; Peptide Hydrolases; Plant Extracts; Plant Leaves; Prodigiosin; Pyocyanine; Quorum Sensing; Tea; Virulence Factors