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目的 观察不同浓度哌拉西林/他唑巴坦在体外诱导铜绿假单胞菌释放DNA的情况。方法 选择体外对铜绿假单胞菌菌株敏感的哌拉西林/他唑巴坦为本研究所用抗生素。制备铜绿假单胞菌菌液后,测定其浓度并检测哌拉西林/他唑巴坦最低抑菌浓度(MIC)和最低杀菌浓度(MBC).将不同稀释度的哌拉西林/他唑巴坦加入铜绿假单胞菌菌液中,于37℃下培养4、24h,取其上清液,采用加入SYBRGold染料的DNA电泳法检测其DNA释放情况。 结果 无论有无哌拉西林/他唑巴坦的作用,体外培养4h的铜绿假单胞菌均未测得DNA释放。无哌拉西林/他唑巴坦时,铜绿假单胞菌在体外培养24h可自发释放一定量的DNA分子,其碱基对数目分布在>2 000bp和<100bp两个区域;以第3次测定的MIC(0. 008g/L)为例,哌拉西林/他唑巴坦浓度在亚MIC(0. 002、0. 004g/L)时,诱导铜绿假单胞菌释放的DNA分子碱基对数目仍分布在上述两个区域, 但<100bp的DNA分子明显增多。哌拉西林/他唑巴坦在大于MIC时,仅诱导铜绿假单胞菌释放少量<400bp的DNA.结论 自然生长情况下铜绿假单胞菌可释放一定量的DNA分子。不同浓度的哌拉西林/他唑巴坦诱导铜绿假单胞菌释放的DNA分子,在碱基对数目和分子数量方面均有明显差别。
Objective To observe the different concentrations of piperacillin / tazobactam in vitro induced Pseudomonas aeruginosa DNA release. Methods Piperacillin / tazobactam, which were sensitive to Pseudomonas aeruginosa in vitro, was selected as the antibiotic used in this study. After the preparation of Pseudomonas aeruginosa, the concentration of Pseudomonas aeruginosa was determined and the MIC and MBC of piperacillin / tazobactam were tested.Different dilutions of piperacillin / tazobact Tan added Pseudomonas aeruginosa bacteria solution, cultured at 37 ℃ for 4,24 h, the supernatant was taken, using the addition of SYBRGold DNA electrophoresis test DNA release. Results No release of DNA was detected in Pseudomonas aeruginosa cultured 4 h in vitro with or without piperacillin / tazobactam. In the absence of piperacillin / tazobactam, Pseudomonas aeruginosa could spontaneously release a certain amount of DNA molecules after 24h in vitro, with the number of base pairs distributed in> 2 000bp and <100bp regions. In the third The measured MIC (0.008 g / L) is taken as an example. When the concentration of piperacillin / tazobactam is submicron (0.002,0.004 g / L), the DNA molecule base released by Pseudomonas aeruginosa is induced The number is still distributed in the above two regions, but <100bp DNA molecules increased significantly. Piperacillin / tazobactam at greater than MIC induced only a small amount of <400 bp DNA from Pseudomonas aeruginosa.Conclusion Pseudomonas aeruginosa can release a certain amount of DNA molecules under natural conditions. Different concentrations of piperacillin / tazobactam induced Pseudomonas aeruginosa DNA molecules released in both the number of base pairs and the number of molecules were significantly different.