Background: The aim of this study was to evaluate the antimicrobial efficacy of liposomal meropenem formulation against clinical and laboratory isolates of Pseudomonas aeruginosa. P. aeruginosa isolates were used to determine the MIC and MBC of free and liposomal meropenem. As well as the effect of free and liposomes meropenem compare the minimum biofilm eradication concentration and inhibition of P. aeruginosa motility was assessed.
Results: In this study, the MICs and MBC of liposomal meropenem was more effective against all clinical and laboratory strains were significantly lower than those of free meropenem (6.25 μg/ml vs 100 μg/ml). Furthermore, liposomal meropenem (≥1.5 μg/ml) completely eradicated biofilm in all P. aeruginosa isolates. While the free form of drug could eradicate biofilm formation in most of isolates in ≥6.25 μg/ml concentration. In addition, lower concentrations of liposomal meropenem could inhibit the bacterial motility.
Conclusion: The results clearly indicate that the liposomal formulation of drug is more effective than meropenem alone against antibiotic resistant P. aeruginosa isolates.
Keywords: Antibiotic resistance; P. aeruginosa; liposomal meropenem.