国产美罗培南对主要产β内酰胺酶的革兰阴性杆菌体外抗菌活性

目的:了解国产美罗培南对临床分离的主要产β内酰胺酶革兰阴性杆菌体外抗菌活性。方法:PCR 产物克隆测序及表型筛选试验检测大肠埃希菌、肺炎克雷伯菌及阴沟肠杆菌中头孢菌素酶(AmpC酶)和超广谱β内酰胺酶;用琼脂稀释法或Etest法测定国产及进口美罗培南、亚胺培南、哌拉西林-三唑巴坦及头孢哌酮-舒巴坦对149株革兰阴性杆菌的最低抑菌浓度。结果:产超广谱β内酰胺酶的大肠埃希苗和肺炎克雷菌的基因型主要为CTX-M型,阳性率达92％。国产和进口美罗培南和亚胺培南对产酶大肠埃希菌、肺炎克雷菌和阴沟肠杆菌的敏感率均为100％,对鲍曼不动杆菌敏感率均为93％,对铜绿假单胞菌敏感分别为83％和 76％。结论:国产美罗培南对革兰阴性杆菌在体外有较强的抗菌活性。

Investigation of antibacteriocidal activity of domestic meropenem on β-lactamases-producing gram negativ bacilli in vitro

AIM: To investigate the susceptibility in vitro of domestic meropenem to main f33-lactamase producing gram-negative bacilli. METHODS: The genotypes of the extended spectrum f33-lactamases (ESBLs) and AmpC (3-lactamases in Escherichia coli,Klebsiella pneumoniae and Enterobacter cloaca were delected by the cloning and sequencing of the polymerase chain reaction products and phenotype isolations.Minimal inhibitory concentrations (MIC) of 149 isolates of gram-negative bacilli to imipenem, piperacillin/tazobactam,cefopera-zone/sulbactam and domestic or imported meropenem were determined by agar dilution or Etesl method. RESULTS: The CTX-M gene was the main genotype in Escherichia coli and Klebsiellu pneumoniae ,reaching the positive rate of 92 %. None of Escherichia coli,Klebsiella pneumoniae and Enterob acter cloac isolates were found resistant to meropenem and imipenem. The susceptible rates of Acinetobacter baumatmii to meropenem and imipenem were the same as 93 %,and those of Pseudomonas aeruginosa to meropenem and imipenem were 83 % and 77 %, respectively. CONCLUSION: Domesatic meropenem has strong antimicrobial activity against gram-negative bacilli,wiht no difference to the imported.