Antimicrobial Activity of Chitosan-Coated Ferrous Sulfate–Loaded Nanoliposome Against Pseudomonas aeruginosa and Bacillus cereus

Iron nanoliposomes with different lecithin/ferrous sulfate ratios (5:1, 10:1, and 20:1 w/w) were prepared by thin-layer hydration sonication, coated with nanochitosan (0.2% w/v), and then characterized based on the antimicrobial activities. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ferrous sulfate against Pseudomonas aeruginosa ATCC 9027 and Bacillus cereus ATCC 11778 were 1000 and 1500 mg/L, respectively. Incorporating ferrous sulfate into the nanoliposome lowered its MIC and MBC values. The optical density (OD₆₀₀) of P. aeruginosa (0.748) and B. cereus (0.742) in the control culture exposed to free ferrous sulfate and ferrous sulfate–loaded nanoliposomes with different levels of lecithin to ferrous sulfate (5:1, 10:1, and 20:1 w/w) at MIC values was decreased around 18.44% and 24.39%, 39.03% and 39.62%, 55.21% and 51.48%, and 66.71% and 70.61%, respectively. Exposure to free ferrous sulfate and ferrous sulfate–loaded nanoliposomes decreased AUC and increased the lag phase of P. aeruginosa and B. cereus (p < 0.05). Moreover, the optical density and AUC of both bacteria which were exposed to chitosan-coated ferrous sulfate–loaded nanoliposomes compared to uncoated nanoliposomes reduced significantly. The highest percentage reduction in final optical density and the lowest AUC of P. aeruginosa and B. cereus cultures were observed after being exposed to chitosan-coated nanoliposomes prepared at lecithin:ferrous sulfate ratio of 20:1 (w/w).