耐碳青霉烯类革兰阴性菌分布特征及耐药性分析

Distribution and drug resistance of carbapenem-resistant gram-negative bacteria

目的了解临床分离的耐碳青霉烯类革兰阴性菌的分布特征及耐药特点,为临床合理使用抗菌药物提供理论依据。方法收集2016年1月-12月耐碳青霉烯类革兰阴性菌临床分离株,采用自动化仪器法和K-B纸片扩散法对上述菌株进行药物敏感性试验,药敏结果依据美国临床实验室标准化协会(CLSI)2016年版的要求进行判断。结果共收集耐碳青霉烯类革兰阴性菌722株,其中耐碳青霉烯类肠杆菌(CRE)52株,耐碳青霉烯类鲍氏不动杆菌(CRAB)492株,耐碳青霉烯类铜绿假单胞菌(CRPA)178株;痰标本检出耐碳青霉烯类病原菌最多,为560株占77.6%,主要来自重症监护病房,以>60岁老年患者居多;CRE和CRAB对阿米卡星和替加环素敏感率较高(67.7%~86.5%),对头孢菌素类、喹诺酮类和加酶抑制剂类抗菌药物敏感率均≤23.1%;CRPA除对碳青霉烯类敏感率低外,对头孢菌素类、喹诺酮类和氨基糖苷类抗菌药物敏感率较高,均≥55.1%;CRE对阿米卡星、替加环素和亚胺培南的MIC值主要分布在≤2μg/ml(58%)、≤0.5μg/ml(52%)、≥16μg/ml(48%);CRAB对阿米卡星的MIC值主要分布在4μg/ml(24.4%)、8μg/ml(27.4%)和≥64μg/ml(28.9%),亚胺培南和替加环素的MIC值主要分布在≥16μg/ml(96.7%)、4μg/ml(47.4%);CRAB对阿米卡星、亚胺培南的MIC值集中在≤2μg/ml(53.4%)、≥16μg/ml(69.7%)。结论耐碳青霉烯类革兰阴性菌对常见抗菌药物敏感性较低,临床医生应根据实验室结果及MIC值合理使用抗菌药物,以减少或延缓耐碳青霉烯类细菌的产生。

OBJECTIVE To investigate the distribution and drug resistance of clinical isolates of carbapenem-resistant gram-negative bacteria so as to provide theoretical basis for reasonable clinical use of antibiotics.METHODS The clinical isolates of carbapenem-resistant gram-negative bacteria were collected from Jan 2016 to Dec 2016,the drug susceptibility testing was performed for the strains by using automated instrument method and K-B disk diffusion method,and the results of the drug susceptibility testing were interpreted based on the criteria of Clinical and Laboratory Standards Institute（CLSI）,2016 Edition.RESULTS A total of 722 strains of carbapenem-resistant gram-negative bacteria were collected,including 52 strains of carbapenem-resistant Enterobacter（CRE）,492 strains of carbapenem-resistant Acinetobacter baumannii（CRAB）and 178 strains of carbapenem-resistant Pseudomonas aeruginosa（CRPA）.Totally 560（77.6%）strains of carbapenem-resistant pathogens were isolated from sputum specimens,most of which were obtained from the elderly patients aged more than 60 years old in the intensive care unit.The drug susceptibility rates of the CRE and CRAB strains to amikacin and tigecycline ranged between 67.7% and 86.5%,the drug susceptibility rates to cephalosporins,quinolones and antibiotics containing enzyme inhibitors were no more than 23.1%.The drug susceptibility rate of the CRPA strains to carbapenems was low,but the drug susceptibility rates to cephalosporins,quinolones and aminoglycosides were no less than 55.1%.The MICs of amikacin,tigecycline and imipenem against CRE strains were no more than 2μg/ml（58%）,no more than 0.5μg/ml（52%）and no less than 16μg/ml（48%）.The MIC of amikacin against CRAB strains was 4μg/ml（24.4%）,8μg/ml（27.4%）and no less than 64μg/ml（28.9%）;the MICs of imipenem and tigecycline were no less than 16μg/ml（96.7%）and 4μg/ml（47.4%）;the MICs of amikacin and imipenem against the CRAB strains were no less than 2μg/ml（53.4%）and no less than 16μg/ml（69.7%）.CONCLUSION The drug susceptibility rates of the carbapenem-resistant gram-negative bacteria to the common antibiotics are low,and it is necessary for clinicians to reasonably use antibiotics based on the results of clinical laboratory tests and MICs so as to reduce or postpone the emergence of the carbapenem-resistant strains.