联合用药对烧伤病房铜绿假单胞菌的体外抗菌活性研究

Study on vitro antimicrobial activity of the combination of antimicrobials against Pseudomonas aeruginosa strains in burn unit

目的探讨环丙沙星、依诺沙星、阿米卡星与临床常用的抗铜绿假单胞菌的β-内酰胺类抗菌药物体外联合的抗菌活性。方法对2001年1月至2006年11月烧伤病房细菌培养与药物敏感试验结果进行回顾性分析,了解铜绿假单胞菌的流行情况。采用棋盘法设计,微量肉汤稀释法测定不同浓度组合的抗菌药物对2006年1～12月在烧伤病房采集的33株铜绿假单胞菌的最低抑菌浓度(MIC),判定联合应用效应。结果6年间我院烧伤病房共分离出652株细菌,其中革兰阴性(G-)杆菌478株,占73.3%,革兰阳性(G+)球菌174株,占26.7%。检出最多的细菌是铜绿假单胞菌149株,鲍曼不动杆菌149株。不同浓度组合的抗菌药物对铜绿假单胞菌的最低抑菌浓度研究提示:环丙沙星、依诺沙星分别与头孢他啶、头孢吡肟、亚胺培南、美罗培南联合主要表现为协同和相加作用。发生协同的比率,环丙沙星组分别为36.4%、30.3%、27.3%、33.3%,依诺沙星组分别为24.2%、27.3%、18.2%、27.3%。阿米卡星与头孢他啶联合用药主要表现为协同作用,协同比率为57.6%,所有的联合均无拮抗作用。结论阿米卡星与头孢他啶联合发生协同的比率高于环丙沙星和依诺沙星,环丙沙星组发生协同的比率大于依诺沙星组,二者差异并无统计学意义(P>0.05)。细菌对抗菌药物耐药的种类越多,联合用药发生协同的比率越少。

Objective To evaluate the antimicrobial activity of ciprofloxacin, enoxaein and amikaein combined with antipseudomonas β-lactams against Pseudomonas aeruginosa strains in vitro. Methods A retrospective analysis was made among the results of bacteria culture and antimicrobial susceptibility testing conducted in burn units from Jan. 2001 to Nov. 2006 to investigate the epidemic tendency of Pseudomonas aeruginosa. With the test designed by the chequerboard titration method, the minimal inhibitory concentrations （MICs） of antibiotics to 33 strains of clinically isolated were determined by broth dilution from Jan. 2001 to Dee. 2006. Results Six handred and fifty-two strains of bacteria were isolated, of which 478 （ 73.3% ） strains were Gram negative bacilli （ G - ） , 174 （ 26. 7% ） strains were Gram positive cocci （ G ＋ ）. The most detected bacteria were Pseudomonas aeruginosa （149 strains）,Acinetobacter baumannii （149 strains ）. The study demonstrates that respective combinations of eiprofloxaein and enoxaein with ceftazidime, eefepime, imipenem and meropcnem mainly manifested synergistic and additive effect. The synergistic rate of ciprofloxaein-group was 36.4% ,30. 3% ,27.3% ,33.3% and enoxaein-group was 24.2% ,27. 3% ,18. 2% , 27.3%. The combination of amikaein and eeftazidime displayed mainly synergie effects （57. 6% ）. All combinations did not produce any antagonism action. Conclusions The synergistic rate of amikacin combination with ceftazidime is the highest among three antibiotics. The synergistic rate of ciprofloxacin-group is higher than that of enoxacin-group, but with no significant differences between the two fluoroquinolones （P 〉 0. 05 ）. The more kinds of antimicrobials bacteria can resist, the lower synergistic rate the combination of antimicrobials will achieve.