Journal of Medical Microbiology and Infectious Diseases

en Natural Compounds as Novel Biofilm Inhibitors: Targeting Multidrug-Resistant Bacterial Pathogenesis Anti-microbial agents, resistance and treatment protocols Anti-microbial agents, resistance and treatment protocols Original article Original article <div style="text-align: justify;">Introduction: Biofilm formation by multidrug-resistant (MDR) bacteria confers increased antimicrobial tolerance and contributes to persistent infections, presenting significant therapeutic challenges. These challenges have driven research into natural compounds that may target key processes, including efflux pump activity, quorum sensing, bacterial adhesion, and biofilm development. This study investigates the anti-biofilm efficacy of six naturally occurring compounds—berberine, chitosan, curcumin, eugenol, linoleic acid, and reserpine—against clinically relevant aerobic MDR bacterial pathogens. Methods: Biofilm formation was evaluated in 200 MDR clinical isolates, including isolates of Escherichia coli (n=49), Klebsiella pneumoniae (n=46), Acinetobacter baumannii (n=24), Pseudomonas aeruginosa (n=29), Staphylococcus aureus (n=25), and Staphylococcus epidermidis (n=27), sourced from various clinical specimens, including pus, urine, blood, and sputum. Biofilm production was quantified using the modified tissue culture plate (MTCP) method. From these isolates, 36 strong biofilm-forming isolates were selected, and the minimum biofilm inhibitory concentration (MBIC) of each compound was determined via a microtiter plate assay with two-fold serial dilutions. Results: Of 200 isolates, 101 (50.5%) exhibited biofilm formation. MBIC values ranged from 0.0156 mg/mL (lowest for eugenol against E. coli and reserpine against E. coli, K. pneumoniae, and S. aureus) to 1 mg/mL (for curcumin against P. aeruginosa and A. baumannii). Eugenol and reserpine showed significantly lower MBICs compared to curcumin (P < 0.05). Eugenol displayed the lowest mean MBIC (0.049 mg/mL) across the 36 selected strong biofilm-forming isolates, followed by reserpine (0.070 mg/mL), while curcumin exhibited the highest mean MBIC (0.583 mg/mL). Linoleic acid demonstrated its lowest MBIC (0.0312 mg/mL) against K. pneumoniae. Conclusion: The tested compounds exhibited variable anti-biofilm potency, with eugenol and reserpine demonstrating the greatest efficacy and curcumin the least, suggesting limited anti-biofilm efficacy at tested concentrations. These findings underscore the potential of eugenol, reserpine, linoleic acid, berberine, and chitosan as promising in vitro anti-biofilm candidates for managing biofilm-associated infections caused by MDR bacteria; however, in vivo efficacy, pharmacokinetics, and safety warrant further investigation in animal models and clinical trials.</div>   Anti-biofilm activity, Berberine, Biofilm, Chitosan, Curcumin, Eugenol, Linoleic acid, Multidrug-resistant (MDR) bacteria, Natural compounds, Reserpine 282 290 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-563-1&slc_lang=en&sid=1 Ankita Jawanpuria ankita.jpuria@gmail.com 0009-0005-1994-6554 Yes Department of Microbiology, Rama Medical College Hospital and Research Centre, Kanpur, Uttar Pradesh, India Shruti Asati shrutiasati@gmail.com 0009-0004-0966-8338 No Department of Microbiology, Netaji Subhash Chandra Bose Medical College, Jabalpur, Madhya Pradesh, India Uma Chaudhary umachaudhary28@gmail.com 0009-0006-3720-9379 No Department of Microbiology, Pandit Bhagwat Dayal Sharma Postgraduate Institute of Medical Sciences, Rohtak, Haryana, India