鲍曼不动杆菌及铜绿假单胞菌体外抗菌活性的分析及培养基的影响

Analysis on vitro antibacterial activity and medium influence of Acinetobacter baumannii and Pseudomonas aeruginosa

目的了解当前鲍曼不动杆菌及铜绿假单胞菌的体外抗菌活性以及在低碱性氨基酸培养基中对碳青霉烯类抗菌药物最低抑菌浓度(MIC)的影响。方法收集临床分离的鲍曼不动杆菌47株、铜绿假单胞菌53株。按美国临床实验室标准化协会(CLSI)琼脂稀释法检测菌株对帕尼培南、亚胺培南、美罗培南、头孢他啶、头孢哌酮-舒巴坦、哌拉西林-他唑巴坦、头孢吡肟、左氧氟沙星、环丙沙星、阿米卡星10种抗菌药物的MIC;同法分别检测鲍曼不动杆菌、铜绿假单胞菌在低碱性氨基酸培养基和水解酪蛋白胨(MH)培养基上对帕尼培南、亚胺培南、美罗培南的敏感性。采用配对t检验比较2组试验结果。结果 47株鲍曼不动杆菌对亚胺培南、左氧氟沙星的耐药率最低,分别是17.10%和14.90%,哌拉西林-他唑巴坦耐药率高达78.70%。53株铜绿假单胞菌对阿米卡星的耐药率最低,为20.75%;头孢他啶的耐药率高达71.70%。在低碱性氨基酸的培养基中,鲍曼不动杆菌和铜绿假单胞菌对碳青霉稀类抗菌药物的敏感性差异有统计学意义(P<0.05)。结论碳青酶烯类药物是治疗鲍曼不动杆菌引起的重症感染的重要药物。由于碱性氨基酸的浓度较高,鲍曼不动杆菌和铜绿假单胞菌对碳青霉烯类抗菌药物的敏感性在使用MH培养基检测时被低估。

Objective To investigate the antibacterial activity of Acinetobacter baumannii and Pseudomonas aeruginosa in vitro,and analyze the minimal inhibitory concentration（MIC） of carbapenems antibiotics in low amino acid medium.Methods A total of 47 Acinetobacter baumannii strains and 53 Pseudomonas aeruginosa strains were collected.According to Clinical and Laboratory Standards Institute（CLSI） standard agar dilution method,the MIC of 10 antibiotics as panipenem,imipenem,meropenem,ceftazidime,cefoperazone-sulbactan,tazobactam-piperacillin,cefepim,levofloxacian,ciprofloxacin and amikacin were determined,and the sensitivities of Acinetobacter baumannii and Pseudomonas aeruginosa to panipenem,imipenem and meropenem in low amino acid medium and Mueller-Hinton（MH） medium were determined.The results of 2 groups were compared by paired t test.Results The resistance rates of imipenem and levofloxacin to 47 Acinetobacter baumannii strains were the lowest（17.10% and 14.90%）.The resistance rate of tazobactam-piperacillin was high as 78.70%.The resistance rate of amikacin to 53 Pseudomonas aeruginosa strains was the lowest（20.75%）,and the resistance rate of ceftazidime was high as 71.70%.The sensitivities of Acinetobacter baumannii and Pseudomonas aeruginosa had statistical significance（P0.05） in low amino acid medium.Conclusions Carbapenems antibiotics have great effect on Acinetobacter baumannii infection diseases.For high concentration of low amino acid,the sensitivity of carbapenems to Acinetobacter baumannii and Pseudomonas aeruginosa is underestimated in MH medium.