An integrative computational and experimental evaluation of natural compounds with potential to target LuxS in Klebsiella pneumoniae.

Klebsiella pneumoniae (KPn) has emerged as a major global health concern due to increasing antimicrobial resistance (AMR). The development of new antimicrobial agents is essential to address multidrug-resistant and emerging hypervirulent strains associated with increased morbidity and mortality worldwide. In this study, an integrative computational-experimental approach was employed to characterise the anti-quorum sensing and anti-biofilm activities of selected natural compounds targeting the LuxS/autoinducer-2 (AI-2) system in KPn. Six compounds were initially screened using homology modelling, molecular docking, pharmacophore analysis, and molecular dynamics (MD) simulations. Resveratrol, quercetin, and epigallocatechin gallate showed favourable binding to LuxS. Although quercetin (ΔG_bind = - 45.47 kcal/mol) and epigallocatechin gallate (- 43.04 kcal/mol) exhibited stronger predicted affinities than resveratrol (- 39.22 kcal/mol), resveratrol demonstrated superior complex stability (RMSD: 1.8 ± 0.2 Å) and persistent interactions with key residues (Tyr63, Trp68). Experimental validation demonstrated that resveratrol exhibited significant antimicrobial activity (MIC/MBC = 32 µg/mL), significantly inhibited quorum sensing-associated phenotypes, and reduced KPn-Acinetobacter baumannii (ABa) dual-species biofilm formation inhibition by 54.7%. These findings identify resveratrol as a promising anti-virulence candidate and highlight the utility of integrative computational and experimental strategies for the identification of compounds targeting quorum sensing and biofilm formation inhibition in multidrug-resistant pathogens.