365例血培养阳性病原菌的分布及其耐药性分析

Distribution and Drug Resistance of Pathogenic Bacteria in 365 Blood Culture Samples

目的了解血培养中病原菌分布及其耐药性。方法采用Bactec 9120血培养仪及凤凰-100全自动细菌鉴定药敏系统对门诊和住院的血培养标本进行病原菌培养鉴定及药敏试验。结果2006年1月-2007年7月血培养共分离菌365株,其中革兰阳性菌116株(31.8%),革兰阴性菌197株(54%),真菌37株(10.1%)。革兰阳性菌以葡萄球菌属为主;革兰阴性菌以肠杆菌科细菌为主(55.8%,110/197),其次为非发酵菌(22.3%,44/197)。大肠埃希菌和肺炎克雷伯菌超广谱β-内酰胺酶(ESBLs)流行率分别为44.8%(30/67)和20.7%(6/29),ESBLs阳性大肠埃希菌和肺炎克雷伯菌对多种抗菌药物耐药率均高于ESBLs阴性细菌;革兰阴性菌对碳青酶烯类抗菌药物仍保持较高的敏感性,培养阳性分布前三位的科室是血液科、小儿科和新生儿科。结论本院血培养阳性结果中条件致病菌所占比例及其耐药性较高,临床医生应及时了解血培养阳性病原菌的分布特征及耐药情况,合理使用抗生素,减少医院感染。

Objective To investigate the distribution and the drug resistance of pathogens isolated from blood samples in our hospital. Methods Blood specimens collected from outpatients and inpatients in our hospital were cultured by Bactec 9120 fluorescent instruments. All strains were isolated and identified by routine methods. Antimicrobial susceptibility testing was conducted on all isolates by using Kirby- Bauer method. Results A total of 365 bacteria strains were isolated from blood culture specimens from January 2006 to July 2007. Gram - positive and gram - negative isolates accounted for 31.8% in： 116） and 54% in=197）, respectively. In addition to, 10.1% （n=37） were fungi. Staphylococcus spp. was the main pathogen among the gram - positive isolates. Of the gram - negative isolates, Enterobacteriaceae accounted for 55.8 % （110/197）, and non - fermentative species accounted for 22.3 % （44/197）. The percentages of ESBLs - producing E. coli and ESBLs- producing K. pneurnoniae were 44.8% （3（I/67） and 20. ？% （6/29）, respectively. Resistance rates of the ESBLs produced in Escherichia coil and Klebsiella pneumoniae were both higher than those of the others. Conclusions The bacteria cultivated from blood specimens have a wide distribution and the percentage of antimicrobial resistance is high in our hospital. Therefore monitoring distribution and drug resistance of pathogens is very important for instructing clinical doctors to use antibiotics properly and reducing nosocomial infection.