肺炎克雷伯菌感染临床分布及其ESBLs介导耐药的特征

Study on the characteristics of clinical distribution and extended spectrum β-lactamases mediated antimicrobial resistance in Klebsiella pneumoniae

目的:了解肺炎克雷伯菌感染临床分布的特点与超广谱β-内酰胺酶(ESBLs)介导耐药的特征。方法:采用K-B纸片扩散法进行药敏试验及ESBLs的表型筛选和确证试验,应用WHONET5.4软件进行数据统计分析。结果:2008年1月至2010年12月临床分离无重复肺炎克雷伯菌336株,标本分布主要为下呼吸道分泌物149株(44.3%)、尿液41株(12.2%)和血液40株(11.9%),科室分布主要为肝胆外科65株(19.3%)、感染科54株(16.1%)和重症监护室40株(11.9%);ESBLs总检出率为43.8%(147/336);产ESBLs菌株对不同种类抗菌药物普遍耐药,且耐药率多明显高于非产ESBLs菌株(P<0.05)。结论:临床上肺炎克雷伯菌主要引起下呼吸道感染,ESBLs是介导其对β-内酰胺类抗菌药物耐药的主要机制之一。产ESBLs菌株呈多重耐药表型特征,临床上治疗该菌感染宜根据药敏与ESBLs检测结果选择抗菌药物。

Objective To investigate the characteristics of clinical distribution and extended spectrum β-lactamases （ESBLs）mediated antimicrobial resistance in Klebsiella pneumoniae （K.pneumoniae）. Methods Antimicrobial susceptibility tests, screening and confirmatory tests for ESBLs were done by Kirby-Bauer disk diffusions method, WHONET 5.4 software was used for data statistic analysis. Results A total of 336 strains of nonrepetitive K.pneumoniae were isolated betweem January 2008 and December 2010. Strains isolated from lower respirator tract secretion, urine and blood were 149 （ 44.3% ）, 41 （ 12.2% ） and 40 （ 11.9% ） respectively. Infections with K.pneumoniae occurred in the department of hepatobiliary surgery, department of infective diseases and department of intensive care unit were 19.3%, 16.1% and 11.9% respectively. The total incident rate of ESBLs producing strains was 43.8%（147/336）. ESBLs producing strains were resistant to most antimicrobial agents, and the resistant rates of them were significantly higher than that of the non-ESBLs producers（P 〈 0.05）. Conclusions K. pneumoniae cause principally infections of lower respiratolT tract in clinic. ESBLs is one of the main mechanisms in which K. pneumoniae resist to β-lactams. ESBLs producing strains have the characteristic of multidrug resistant phenotypes. The antimicrobial agents for treating infections caused by K. pneumonia should be chosen according to the results of the antimicrobial susceptibility and ESBLs confirmatolT tests.