产ESBLs大肠埃希菌的耐药性研究

STUDY ON DRUG RESISTANCE OF EXTENDED SPECTRUM BETA-LACTAMASES-PRODUCING STRAINS OF Escherichia coli

[目的]调查华中科技大学同济医学院附属同济医院大肠埃希菌超广谱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非重复分离大肠埃希菌,标准纸片扩散法检测ESBLs,琼脂稀释法检测其对15种抗菌药物的最低抑菌浓度。[结果]大肠埃希菌超广谱β-内酰胺酶的流行率为32.7%,153株产ESBLs大肠埃希菌对二代头孢菌素的耐药率大于90%;对其他β-内酰胺的耐药率在12.5%～55%之间;对氨基糖苷类的庆大霉素、氟喹诺酮类的环丙沙星、四环素的耐药率在70%～90%之间。上述药物中头孢他啶、阿米卡星的MIC50仍在敏感范围,氨曲南的MIC50已达中介范围,其他抗菌药物的MIC50和MIC90均处于耐药范围。只有碳青霉烯类的亚胺培南全部敏感。产ESBLs和ESBLs阴性大肠埃希菌的耐药率比较:除哌拉西林/他唑巴坦差异无统计学意义,其他抗菌药物差异有统计学意义。[结论]该院大肠埃希菌产ESBLs菌株对多类药物表现出较高的耐药率,仅对碳青霉烯类的亚胺培南全部敏感。

[Objective]To investigate the isolated rate of extended spectrum beta-lactamases carried in Escherichia coli among Tongji Hospital,Huazhong University,and analysis the drug resistance to 15 kinds of antibacterial agents of E.coli.[Methods]A total of 468 strains of Escherichia coli were collected from Tongji hospital affiliated to HuaZhong University of science and technology.The MIC of 15 antibacterial agents against the clinical isolates was detected by double agar dilution method.[Results]153 ESBLs-producing strains were detected in 468 Escherichia coli.The detection rate was 32.7%.For the second generation cephlosporins,the drug resistance rates of the 153 E.coli strains of ESBLs producers were more than 90%.For other cephlosporins,the drug resistance rates were from 12.5% to 55%.For gentamicin,Ciprofloxacin,and tetracycline,the rates of drug resistance were from 70% to 90%.MIC50 of ceftazidime and amikacin were in the range of susceptibility.For aztreonam,MIC50 reached to the rang of intermediary.MIC50 and MIC90 for other antibacterial agents were in the range of resistance.However,all of these ESBLs producers were susceptible to imipenem.The differences in antimicrobial resistance for ESBLs-producing E.coli and non ESBLs-producing E.coli were not statistically significant for amikacin and tetracycline,but were statistically significant for other antibacterial agents[Conclusion]The isolation rates of ESBLs producing in E.coli is 32.7%.Extended spectrum beta-lactamase producers reveal high drug resistance to most of the antibacterial agents.All of these detected strains are only susceptible to imipenem.