Exploring imidazo[4,5-g]quinoline-4,9-dione derivatives as Acinetobacter baumannii efflux pump inhibitor: an in silico approach

Antimicrobial resistance (AMR) is fast becoming a medical crisis affecting the entire global population. World Health Organization (WHO) statistics show that globally 0.7 million people are dying yearly due to the emergence of AMR. By 2050, the expected number of lives lost will be 10 million per year. Acinetobacter baumannii is a dreadful nosocomial pathogen that has developed multidrug resistance (MDR) to several currently prescribed antibiotics worldwide. Overexpression of drug efflux transporters (DETs) is one of the mechanisms of multidrug resistance (MDR) in Acinetobacter baumannii. Therefore, blocking the DET can raise the efficacy of the existing antibiotics by increasing their residence time inside the bacteria. In silico screening of five synthetic compounds against three drug efflux pump from A. baumannii has identified KSA5, a novel imidazo[4,5-g]quinoline-4,9-dione derivative, to block the efflux of antibiotics. Molecular docking and simulation results showed that KSA5 could bind to adeB, adeG, and adeJ by consistently interacting with ligand-binding site residues. KSA5 has a higher binding free energy and a lower HOMO-LUMO energy gap than PA beta N, suggesting a better ability to interact and inhibit DETs. Further analysis showed that KSA5 is a drug-like molecule with optimal physicochemical and ADME properties. Hence, KSA5 could be combined with antibiotics to overcome antimicrobial resistance.

Automated summary

Antimicrobial resistance (AMR) is a global medical crisis, causing millions of deaths annually. Acinetobacter baumannii, a dangerous nosocomial pathogen, has developed resistance to multiple antibiotics. Blocking drug efflux transporters (DETs) can enhance the efficacy of antibiotics, and a compound called KSA5 has been identified to successfully block antibiotic efflux in A. baumannii. KSA5 has optimal physicochemical and ADME properties, making it a promising candidate for overcoming antimicrobial resistance when combined with antibiotics.