Abstract:
Background/Objectives: Mixed bloodstream infections associated with central venous catheter (CVC) use are a growing problem. The aim of this study was to evaluate the activity of a cationic arginine-based gemini surfactant, C9(LA)2, against mixed biofilms of fluconazole-resistant Candida albicans and extended-spectrum beta-lactamase (ESBL)-producing E. coli, and the preventive effect of this surfactant impregnated in CVCs on the formation of inter-kingdom biofilms.
Methods: Broth microdilution assays were performed along with evaluation of the effect against mixed biofilms in formation. The impregnation of CVCs with the surfactant and with a hydrogel containing the cationic surfactant was investigated to assess their potential to prevent the formation of mixed biofilms. Scanning electron microscopy (SEM) was also utilized.
Results: Minimum inhibitory concentrations (MICs) for resistant C. albicans ranged from 4-5.3 µg/mL, while for E. coli, the MICs varied from 85.3 to 298.7 µg/mL. Fungicidal and bactericidal action patterns were obtained. In mixed biofilm formation in 96-well plates, there was a significant reduction in the colony-forming unit (CFU) count. The impregnation of the CVC with C9(LA)2 alone resulted in a biofilm reduction of 62% versus C. albicans and 48.7% against E. coli in terms of CFUs. When the CVC was impregnated with the surfactant hydrogel, the effect was improved with an inhibition of 71.7% for C. albicans and 86.7% for E. coli. The images obtained by SEM corroborated the results.
Conclusions: C9(LA)2 has potential for use in CVC impregnation to prevent the formation of mixed biofilms of fluconazole-resistant C. albicans and ESBL-producing E. coli.
Reference:Pérez L, da Silva CR, do Amaral Valente Sá LG, Neto JBA, Cabral VPF, Rodrigues DS, Moreira LEA, Silveira MJCB, Ferreira TL, da Silva AR, Cavalcanti BC, Ricardo NMPS, Rodrigues FAM, Júnior HVN. Preventive Activity of an Arginine-Based Surfactant on the Formation of Mixed Biofilms of Fluconazole-Resistant Candida albicans and Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli on Central Venous Catheters. Antibiotics (Basel). 2025 Feb 24;14(3):227. doi: 10.3390/antibiotics14030227. PMID: 40149039; PMCID: PMC11939339.