Antimycobacterial Drugs as a Novel Strategy to Inhibit Pseudomonas aeruginosa Virulence Factors and Combat Antibiotic Resistance: A Molecular Simulation Study

Antimicrobial resistance poses a severe threat, particularly in developing countries where the ready availability of drugs and increased consumption lead to improper antibiotic usage, thereby causing a surge in resistance levels compared to developed areas. Despite the past success of antibiotics, their effectiveness diminishes with regular use, posing a significant threat to medical efficacy. Pseudomonas aeruginosa, an opportunistic pathogen, triggers various infection-related issues, occurring on occasions including chronic wounds, burn injuries, respiratory problems in cystic fibrosis, and corneal infections. Targeting the quorum sensing (QS) of P. aeruginosa emerges as a strategic approach to combat infections caused by this bacterium. The objective of this study was to check the effect of antimycobacterial drugs against the potential QS targets in P. aeruginosa and identify lead candidates. The antimycobacterial drugs were first examined for the toxicological and pharmacokinetic profile. By virtual screening through molecular docking, delamanid and pretomanid stood out as major candidates. The binding energies of delamanid and pretomanid with LasR were determined to be −8.3 and −10.9 kcal/mol, respectively. The detailed analysis of the complexes of lead compounds were examined through molecular dynamics simulations. The molecular simulations data validated a sustained interaction of lead drugs with target proteins (PqsR, LasI, and LasA) in a physiological environment. The negligible changes in the secondary structure of proteins in presence of hit antimycobacterial drugs further strengthened the stability of the complexes. These findings highlight the potential repurposing of delamanid and pretomanid, specifically in targeting P. aeruginosa quorum-sensing mechanisms.