美罗培南和其他4种β内酰胺类抗生素体外抗菌活性的研究

Comparison of in vitro antibacterial activity of meropenem with four other β lactams

目的 :调查美罗培南和其他 4种 β内酰胺类抗生素的体外抗菌活性。 方法 :采用Etest法测定美罗培南、亚胺培南、头孢吡肟、头孢他啶和头孢哌酮 舒巴坦对 5 5 4株临床分离菌株的最低抑菌浓度 (MIC) ;检测肺炎克雷伯菌和大肠埃希菌中产超广谱 β内酰胺酶 (ESBLs)。 结果 :11.5 %的大肠埃希菌和 2 9%的肺炎克雷伯菌产生ESBLs。头孢吡肟、头孢哌酮 舒巴坦和头孢他啶对ESBLs阳性菌的MIC值明显高于ESBLs阴性株 ;而美罗培南和亚胺培南对产ESBLs株和不产ESBLs株的MIC值没有明显差别。对于肠杆菌属细菌 ,美罗培南的活性最高 (敏感率 95 % ) ,其次是亚胺培南 (82 % )、头孢吡肟 (71% )、头孢他啶、头孢哌酮 舒巴坦 (5 7%～ 5 9% )。美罗培南对于铜绿假单胞菌的MIC仅为亚胺培南的 1/ 8;对于不动杆菌属、肠球菌属 ,这 2种碳青霉烯类的MIC值分布相似。美罗培南对流感嗜血杆菌、肺炎链球菌和苯唑西林敏感的葡萄球菌的抗菌活性很高。结论 :5种β内酰胺类抗生素类的活性依次是美罗培南 (敏感率 94 .6 % )、亚胺培南 (90 .1% )、头孢吡肟 (77.6 % )、头孢哌酮 舒巴坦 (77.5 % )及头孢他啶 (76 .6 % )。

Objective: To investigate the in vitro activity of meropenem and four other β lactams. Methods: The minimum inhibitory concentration(MIC) of meropenem, imipenem, ceftazidime, cefepime, and cefoperazone /sulbactam on 554 clinical isolates were determined by E test method. The extended spectrum β lactamase (ESBLs) producing strains in Escherichia coli and Klebsiella pneumoniae were detected by ESBLs phenotype screen and confimatory method recommended by the National Committee for Clinical Laboratory Standards. Results: Eleven percent of Escherichia coli and 29% of Klebsiella pneumoniae produced ESBLs. The MICs of cefepime, cefoperazone sulbactam, and ceftazidime on ESBLs producing strains were significantly higher than those on nonESBLs producing strains;there was no significant difference between the anti bacterial activity of meropenem and imipenem against ESBLs producing and ESBLs non producing strains. Against Enterobacter spp, meropenem was the most active agent(95% susceptible),followed by imipenem (82%), cefepime (71%), ceftazidime, and cefoperazone sulbactam (57%-59%).The MIC of meropenem againct Pseudomonas aeruginosa was one eighth that of imipenem; the distribution of MIC of the two drugs was similar for Acinetobacter spp. and Enterococcus spp.. Meropenem had excellent activity against Haemophilus influenzae, Streptococcus pneumoniae, and oxacillin susceptible Staphylococci. Conclusions: The order of activity of the five agents was: meropenem(94.6% susceptible)>imipenem (90.1%)>cefepime (77.6%), cefoperazone /sulbactam (77.5%) and ceftazidime (77.6%).