“Extensively drug-resistant (XDR) Acinetobacter baumannii poses a serious clinical challenge due to its resistance to nearly all available antibiotics, including carbapenems and colistin. Cannabidiol (CBD), a non-psychoactive phytochemical from Cannabis sativa L., has recently shown promising antimicrobial activity.
This study evaluates the antibacterial and anti-biofilm effects of CBD against XDR A. baumannii isolates and explores its mechanism of action and potential as an adjunct therapeutic agent.
Twenty-six A. baumannii isolates collected from ICU medical devices were identified using MALDI-TOF/MS. Antimicrobial susceptibility was assessed by disk diffusion and broth microdilution to determine MICs and MBCs for CBD and standard antibiotics. Synergistic effects were evaluated via checkerboard assays and FICI values. Biofilm inhibition and eradication were assessed using crystal violet and MTT assays. Time-kill studies, membrane integrity assays (DNA/protein leakage, NPN uptake, membrane depolarization), and scanning electron microscopy (SEM) were employed to investigate bactericidal kinetics and membrane-disruptive mechanisms.
CBD exhibited activity against antimicrobial resistance isolates (MIC: 3.9 to > 500 µg/mL). Remarkably, CBD synergized with gentamicin, meropenem, and colistin, reducing their effective concentrations by up to 1,000-fold. Combination therapy significantly inhibited and eradicated biofilms. Time-kill assays demonstrated rapid, concentration-dependent killing, with complete bacterial clearance at 4× MIC within 2 h. Mechanistic assays and SEM confirmed that CBD induces extensive membrane damage.
These findings highlight CBD’s potential as an effective adjunct to conventional antibiotics for treating XDR A. baumannii infections, offering a novel strategy to counteract antimicrobial resistance.”
https://pubmed.ncbi.nlm.nih.gov/40817249/
“Acinetobacter baumannii is an opportunistic, Gram-negative bacterium that has emerged as a major cause of hospital-associated infections (HAIs) worldwide, with no standard therapeutic recommendation for its management and control. It primarily affects critically ill and immunocompromised patients, leading to severe infections such as ventilator-associated pneumonia, bloodstream infections, urinary tract infections, meningitis, and wound infections. A. baumannii’s remarkable ability to survive in hospital environments, resist desiccation, and persist on medical equipment—particularly in intensive care units (ICUs)—makes it a persistent challenge in healthcare settings.”
“Our study demonstrates that CBD exhibits potent antibacterial and anti-biofilm properties against XDR A. baumannii, particularly when used in combination with conventional antibiotics such as gentamicin, meropenem, and colistin. Notably, its ability to disrupt membrane integrity represents a key mechanism in overcoming drug tolerance.
These findings provide a strong foundation for further investigation of CBD as a novel therapeutic strategy to combat antimicrobial resistance in clinical settings.”
https://bmccomplementmedtherapies.biomedcentral.com/articles/10.1186/s12906-025-05056-w