Phytochemical‑driven antibiofilm effects of <i>Ruellia tuberosa L.</i> against <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i>

Multidrug-resistant Gram-negative pathogens, including Escherichia coli (E.coli) and Klebsiella pneumoniae (K.pneumoniae) represent major clinical concerns due to their potent biofilm-forming ability and associated virulence traits that contribute to persistent infections and antibiotic failure.In response to the growing limitations of conventional antibiotics against biofilm-associated infections, the present study evaluated the antibiofilm potential of the ethanolic leaf extract of Ruellia tuberosa L. (R. tuberosa L.) using in vitro assays and gas chromatography-mass spectrometry-guided molecular docking analysis.The extract demonstrated antibacterial activity at the minimum inhibitory concentration (MIC) level and effectively inhibited biofilm formation at sub-MIC concentrations, achieving 55% inhibition in E. coli at 10 mg/ml and 67.81% inhibition in K. pneumoniae at 20 mg/ml, without significantly affecting planktonic growth.Phytochemical profiling revealed a diverse compound composition, with diethyl phthalate identified as the major constituent.Molecular docking demonstrated stable interactions of this compound with key biofilm-and virulence-associated targets in both pathogens, suggesting interference with bacterial adhesion, biofilm development, and persistence.Overall, these findings highlight R. tuberosa L. as a promising natural source of antibiofilm agents capable of attenuating biofilm formation in multidrug-resistan Gram-negative pathogens.These plant-derived compound may serve as adjunct strategies for managing biofilm-associated infections caused by E. coli and K. pneumoniae, warranting further in vivo and molecular validation.