Innovative microparticle strategies: harnessing essential oil-loaded lecithin/chitosan systems against Burkholderia pseudomallei.

Burkholderia pseudomallei, the causative agent of melioidosis, presents high antimicrobial resistance, largely due to its biofilm-forming ability. Here, innovative lecithin/chitosan microparticles loaded with lemongrass (LEO) and geranium (GEO) essential oils (LEOLCN and GEOLCN) were developed and characterized as a novel strategy to combat B. pseudomallei. Microparticles were characterized and evaluated for their effects on planktonic growth and biofilm inhibition, as well as for potential synergistic interactions with antibiotics. Microparticles exhibited a spherical morphology, high encapsulation efficiency, and sustained release profiles, with up to 45% of EO released at pH 2.0 and 32% at pH 7.4 after 50 h. LEOLCN demonstrated MICs ranging from 64 to 128 µg ml-1 for most strains, although some resistant isolates exhibited MICs of up to 2,048 µg ml-1. At a concentration of 512 µg ml-1, both LEOLCN and GEOLCN reduced biofilm biomass and metabolic activity by more than 50%. LEOLCN exhibited synergistic effects with conventional antibiotics, reducing ceftazidime MICs by 2- to 9-fold, suggesting its potential to enhance antibiotic therapy against resistant strains. Scanning electron microscopy confirmed biofilm disruption. Overall, the dual antimicrobial and antibiofilm action of these compounds introduces a promising and innovative in vitro platform to address the persistent challenge of B. pseudomallei infections and biofilm-associated resistance.