Unexpected Efficacy of Albumin-Bound Glycerol Monolaurate Against Multidrug-Resistant Bacterial Isolates: A Time-Kill Assay Study.

BACKGROUND: The rise of antibiotic resistance is a significant threat to global health, necessitating the exploration of novel antimicrobial agents. Glycerol monolaurate (GML) is known for its antimicrobial properties, primarily against Gram-positive bacteria, with limited evidence of efficacy against Gram-negative pathogens. METHODS: This study evaluated the antibacterial activity of GML alone and in combination with human serum albumin (HSA) against clinical isolates of carbapenem-resistant and vancomycin-resistant bacteria using MIC and time-kill assays. RESULTS: Contrary to previous reports, we demonstrate that GML exhibits significant antibacterial activity against Gram-negative bacteria, including strains resistant to conventional antibiotics. It inhibited carbapenem-resistant isolates with MIC values ranging from 25 to 100 μg/mL for E. coli, K. pneumoniae, and E. cloacae and showed bacteriostatic and bactericidal activity. The combination of HSA and GML enhanced this effect, showing potent bactericidal properties across all tested concentrations. CONCLUSION: Current findings suggest that HSA-bound GML could be developed as a novel broad-spectrum antimicrobial agent targeting multidrug-resistant pathogens. Future research should focus on formulation optimization, in vivo efficacy studies, and preclinical evaluations to determine its therapeutic potential in clinical settings.