住院新生儿感染大肠埃希菌耐药性分析

Antimicrobial resistance analysis of clinical Escherichia coli isolates in hospitalized neonates

目的分析住院新生儿临床标本中分离的大肠埃希菌对抗菌药物的耐药性状况,寻找新生儿病房大肠埃希菌耐药基因来源,为临床合理用药提供依据。方法收集2009年9月至2011年11月本院住院新生儿的临床标本,将从中分离的大肠埃希菌作为研究对象,采用纸片扩散法(K-B法)检测大肠埃希菌对8种抗生素的耐药性。结果共分离出100株大肠埃希菌,这些菌株对8种抗菌药物的耐药率从高到低依次为头孢噻肟(67%)、四环素(58%)、左氧氟沙星(34%)、头孢吡肟(33%)、头孢西丁(26%)、氯霉素(19%)、阿米卡星(13%),未发现对美罗培南耐药的菌株。100株大肠埃希菌超广谱β-内酰胺酶(ESBLs)检出率为55%,痰液大肠埃希菌菌株ESBL检出率为65%,明显高于无菌体液(血液、脑脊液)的27%。产ESBL大肠埃希菌菌株对头孢噻肟、头孢吡肟的耐药率明显高于非产ESBL大肠埃希菌菌株。大肠埃希菌多重耐药率为15%,耐药谱型以β-内酰胺类、氨基糖苷类、喹诺酮类、氯霉素类、四环素为主,占8%。结论住院新生儿临床送检标本中,大肠埃希菌对头孢类抗生素耐药情况严重,对大肠埃希菌的耐药率及耐药模式进行连续监测,对于临床用药有重要价值。

Objective To study the antibiotic resistance of clinical Escherichia eoli （E. coli） isolates from hospitalized newborns, to explore the sources of E. eoli resistance genes, and to provide clinical guidance for antibiotic usage. Methods A retrospective study of microbiologically tested samples （blood, cerebrospinal fluid, sputum, skin swabs ） taken from newborns hospitalized for suspected infection in the Neonatal Ward in Beijing Children＇s Hospital was conducted. The period of study was 26 months, from September 1st, 2009 to November 31st, 2011. The disc diffusion method （K-B） was used to detect the resistance of E. coli to eight types of antibiotics. Results One hundred cultured samples were classified as E. coli in the study period. 67% of E. coli isolates were resistant to cefotaxime, 58% to tetracycline, 13% -34% to amikacin, chloramphenicol, cefoxitin, cefepime and levofloxacin. There was no meropenem resistant strains. The prevalence of extended-spectrum β-1actamases （ESBLs） in E. coli was 55%, the rate in sputum was 65%, was relatively higher than that in sterile body fluids （blood and cerebrospinal fluid）, the latter was 27%. Resistance rate of ESBL produced E. coli strains to cefotaxime and cefepime were significantly higher than that without ESBL The multi-drug resistance rate was 15%. Beta-lactam antibiotic, amikacin, levofloxacin,chloramphenicol, tetracycline were predominant drug resistance patterns, accounted for 8% （8/100）. Conclusions The resistance of E. coli to cephalosporin was very serious. Continuous monitoring of E. coli and its antibiotic susceptibility pattern is necessary for clinical medication.