Preparation and investigation of in vitro effect of liposomal ceftazidime on the resistant Pseudomonas aeruginosa

The resistance of bacteria to β-Lactam antibiotics produces many problems in the treatment of bacterial infections. Although Ceftazidime is an extended antibiotic spectrum, it becomes inactive against β-Lactamase produced of Pseudomonas aeruginosa. This study clears how Liposome protects Ceftazidime hydrolysis by β-Lactamase. For preparing Large Unilamellar Vesicles, Phosphatidylcholine and Cholesterol are solved in Ether and then Ceftazidime is added to this mixture, and after affecting this mixture by Sonicator, the uniform suspension is produced and then evaporates under vacuum condition in Rotary Evaporator until the thin layer is remained around the basin. It is used from dialysis method for isolating this drug which is entered in Liposome of outside drug and these Large Unilamellar Vesicles are seen by the lighting microscope. This bacterium is standard strain of Pseudomonas aeruginosa (ATCC 27853). 106 Ladan Farzampanah et al. Ceftazidime Minimum Inhibitory Concentration (MIC) for standard Pseudomonas aeruginosa is 2μg/ml that shows high resistance of bacteria to Ceftazidime, but liposomal Ceftazidime MIC decreases to 0/5μg/ml. All the tests were done for 3 times and every time the result approved the right effect of the before result. Furthermore the deduction of growing bacteria in existence of liposomal Ceftazidime was observed in its natural curve. This study shows the positive effects of these entered β-Lactam antibiotics inside Liposomes in vitro condition. Attending resistance of these bacteria that produce β-Lactamase, this method can be used for better treatment in the future.