Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
Eur J Clin Microbiol Infect Dis. 2012 Aug;31(8):1931-9. doi: 10.1007/s10096-011-1523-4. Epub 2011 Dec 31.
We investigated the performance of cefotaxime for the detection of extended-spectrum β-lactamase (ESBL) or plasmid-mediated AmpC β-lactamase (pAmpC) and the clinical characteristics of cefotaxime-non-susceptible Escherichia coli or Klebsiella pneumoniae (CTXNS-EK) bacteraemia. All of the consecutive bloodstream isolates between 2005 and 2010 in a Japanese university hospital were characterised using polymerase chain reaction (PCR). Risk factors and outcomes of CTXNS-EK were analysed by multivariate logistic regression analysis. We identified 58 CTXNS-EK (15.6%) from 249 E. coli and 122 K. pneumoniae. Cefotaxime with a minimum inhibitory concentration (MIC) of >1 μg/mL had a sensitivity of 98.3% and a specificity of 99.7% for the detection of ESBL or pAmpC. CTXNS-EK had increased from 4.5% in 2005 to 23% in 2009. Risk factors for CTXNS-EK were previous isolation of multidrug-resistant bacteria, use of oxyimino-cephalosporins or fluoroquinolones, and high Sequential Organ Failure Assessment (SOFA) score. Patients with CTXNS-EK bacteraemia less frequently received appropriate empirical therapy than patients with cefotaxime-susceptible EK bacteraemia (81% vs. 97%, p<0.001) and died within 30 days (21% vs. 5%, p=0.001). Using the current breakpoints of the Clinical and Laboratory Standards Institute (CLSI) or the European Committee on Antimicrobial Susceptibility Testing (EUCAST), cefotaxime alone can identify ESBL or pAmpC producers. CTXNS-EK is an important and increasingly prevalent bacteraemia pathogen.
我们研究了头孢噻肟在检测超广谱β-内酰胺酶（ESBL）或质粒介导的AmpC β-内酰胺酶（pAmpC）中的性能，以及头孢噻肟不敏感的大肠埃希菌或肺炎克雷伯菌（CTXNS-EK）菌血症的临床特征。在日本一家大学医院，对 2005 年至 2010 年连续的血流分离株进行了聚合酶链反应（PCR）鉴定。采用多变量逻辑回归分析方法分析 CTXNS-EK 的危险因素和结局。我们从 249 株大肠埃希菌和 122 株肺炎克雷伯菌中鉴定出 58 株 CTXNS-EK（15.6%）。头孢噻肟的最低抑菌浓度（MIC）>1μg/mL 时，检测 ESBL 或 pAmpC 的灵敏度为 98.3%，特异性为 99.7%。CTXNS-EK 从 2005 年的 4.5%增加到 2009 年的 23%。CTXNS-EK 的危险因素包括以前分离出的多药耐药菌、使用肟型头孢菌素或氟喹诺酮类药物以及高序贯器官衰竭评估（SOFA）评分。CTXNS-EK 菌血症患者接受经验性治疗的比例低于头孢噻肟敏感的 EK 菌血症患者（81% vs. 97%，p<0.001），30 天内死亡率（21% vs. 5%，p=0.001）更高。根据临床和实验室标准协会（CLSI）或欧洲抗菌药物敏感性测试委员会（EUCAST）的现行折点，头孢噻肟本身可以识别 ESBL 或 pAmpC 产生菌。CTXNS-EK 是一种重要且日益流行的菌血症病原体。
