Background and Aim: Pseudomonas aeruginosa is an opportunistic gram - negative bacillus commonly associated with wide range of diseases. In this study we aim to evaluate the antibacterial activity of liposomal meropenem against to clinical isolates of Pseudomonas aeruginosa. P. aeruginosa strains were used to determine the MIC and MBC of free and liposomal meropenem. Also the effect of free and liposomes antibiotic to compare the minimum biofilm eradication concentration and inhibit ion of P. aeruginosa motility was assessed.
Methods: Meropenem - loaded liposomal formulations were prepared according to the modified ethanol injection method. A broth micro - dilution method was used to determine the MICs of free and liposomal meropenem. Also free or liposomal meropenem at 1/8 of the MIC was added to agar plates, and motility was examined.
Results: In this study the MICs and MBC of liposomal meropenem was more effective against all clinical strains were significantly lower than those of free meropenem (6.25μg/ml vs 100μg/ml). Additionally liposomal formulation of drug (?1.5 μg/ml) completely eradicated biofilm in all P. aeruginosa isolates. While the free form of antibiotic could eradicate biofilm formation in most of isolates in ?6.25 μg/ml c oncentration. Moreover lower concentrations of liposomal meropenem could inhibit the bacterial motility.
Conclusion: The results obviously indicate that the liposomal formulation of drug is more effective than free form of meropenem against antibiotic resi stant of P. aeruginosa isolates.