产超广谱β-内酰胺酶肺炎克雷伯菌的耐药性研究

目的调查华中科技大学同济医学院附属同济医院肺炎克雷伯菌超广谱β-内酰胺酶的流行情况,分析产超广谱β-内酰胺酶细菌的耐药性。方法选择华中科技大学同济医学院附属同济医院细菌室2004年1-12月非重复分离肺炎克雷伯菌218株,标准纸片扩散法检测超广谱β-内酰胺酶,琼脂稀释法检测其对15种抗菌药物的最低抑菌浓度。结果肺炎克雷伯菌超广谱β-内酰胺酶的流行率36.2%(79/218)。79株产ESBLs肺炎克雷伯菌对二代头孢菌素的耐药率大于90%;三代头孢头孢他啶的耐药率为41.0%,头孢噻肟的耐药率为61.0%;四代头孢(头孢吡肟)的耐药率为23.4%;头霉素类的头孢西丁的耐药率为58.5%;单环β-内酰胺类的氨曲南的耐药率为70.7%;三种含酶抑制剂抗菌药物的耐药率为26.8%～55.1%;氟喹诺酮类的环丙沙星、氨基糖苷类的庆大霉素、四环素的耐药率在55%～65%之间。上述所有抗菌药物的MIC50和MIC90均处于耐药范围。产超广谱β-内酰胺酶和超广谱β-内酰胺酶阴性肺炎克雷伯菌的耐药率比较:阿米卡星差异有显著性,其他抗菌药物差异有极显著性。结论同济医院肺炎克雷伯菌超广谱β-内酰胺酶的流行率36.2%,产超广谱β-内酰胺酶菌株对头孢菌素类、头霉素类、单环β-内酰胺类抗菌药物、含酶抑制剂药物、氟喹诺酮类及氨基糖苷类药物表现出较高的耐药率,仅碳青霉烯类的亚胺培南全部敏感。

Studies on Antimicrobial Resistance of Extended Spectrum Beta - lactamases - producing Strains in Klebsiella Pneumoniae

Objective To investigate the isolated rate of extended spectrum beta-lactamases carried in Klebsiella pneumoniae in Tongji Hospital Affiliated to Tongji Medical College,Huazhong University of Science and Technology,and to analyze their drug resistance to 15 kinds of antibacterial agents.Methods A total of 218 strains of Klebsiella pneumoniae from January,2004 to December,2004 were isolated from Tongji Hospital.The minimum inhibitory concentration of 15 antibacterial agents against the clinical isolates was detected by double agar dilution method.Results The drug resistance rates of 79 K.pneumoniae strains of ESBLs producers to second generation cephalosporins were exceeded 90%;to third generation cephalosporins,the drug resistance were 41.0% to 61.0%,and to forth generation cephalosporin-cefepime 23.4%.For cefoxitin,aztreonam,amocillin/clavulanic acid,cefoperazone/sulbactam,and piperacillin/tazobactam,the drug resistance rates were from 26.8% to 70.7%.For gentamicin,ciprofloxacin,and tetracycline,the drug resistance rates were between 55% and 65%.MIC50 and MIC90 for all of these antibacterial agents were in resistance.The difference for ESBLs-producing K.pneumoniae comparied with non ESBLs-producing K.pneumoniae in amikacin was significant,to other antibacterial agents was highly significant.Conclusion The prevalence of ESBLs-producing in K.pneumoniae was 36.2%(79/218).Extended spectrum beta-lactamase producers show more prominent drug resistances to cephalosporins,monobactams,beta-lactam/beta-lactamase inhibitor combinations,aminoglycosides and fluorquinolones,while all of these detected strains remain susceptible to imipenem.