住院患者血培养病原菌的分布及耐药性分析

Analysis of drug resistance and distribution of pathogens isolated from blood cultures

目的分析住院患者血培养分离的病原菌分布特点及耐药状况,指导临床合理用药。方法收集2012年1-12月于绵阳市中心医院各科住院患者共7716份血培养标本中分离出的692株病原菌(剔除重复菌株),采用Bact/ALERT 3D全自动血培养仪进行血液培养,VITEK 2 Compact全自动微生物分析仪进行微生物鉴定和药物敏感试验。结果病原菌阳性检出率为8.97%(692/7716)。其中革兰阴性菌395株,占57.08%;革兰阳性菌278株,占40.17%;真菌19株,占2.75%。最常见的病原菌依次为大肠埃希菌(n=181)、凝固酶阴性葡萄球菌(n=165)、肺炎克雷伯菌(n=96)、金黄色葡萄球菌(n=45)、肠球菌(n=26)等。检出的葡萄球菌中耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)的检出率分别为20%和83.4%,未发现万古霉素、利奈唑胺耐药葡萄球菌。肠球菌对万古霉素耐药率为7.7%,未发现利奈唑胺、替加环素耐药肠球菌。肠杆菌科细菌对碳青霉烯类抗菌药物高度敏感,大肠埃希菌及肺炎克雷伯菌产超广谱β-内酰胺酶(ESBLs)的比率分别为45.0%和22.9%。非发酵菌对多种抗菌药物耐药率高。结论血培养中检出的病原菌种类较多,细菌耐药现象较为普遍,临床医师应高度重视血培养,根据药敏结果合理使用抗菌药物。

Objective To investigate the distribution and antibiotic resistance of pathogens isolated in blood culture from the inpatients, which can be used to guide clinical therapy. Methods Bact/ALERT 3D System was used to perform blood culture ,and VITEK 2 Compact Instrument was used to identify Bacteria and to test antimicrobial susceptibility. Results Among 7 716 blood culture samples, the rate of positive cultures was 8.97% （692/7 716）. Moreover,395 strains were Gram-negative bacteria （57.08%）, 278 strains were Gram-positive bacteria（40.17% ） and 19 strains were fungi （2.75%）. Escherichia coli, Coagulase negative Staphylococcus, Klebsiella pneumoniae , Staphylococcus aureus and Enterococcus were the most common isolates. The incidences of meticillin-resistant S. aureus （MRSA） and meticillinresistant coagulase negative Staphylococcus （MRCNS） were 20% and 83.4%, respectively. No vancomycin and linezolid resistant Staphylococcus strains were found. There were 7.7% of Enterococcus resistant to vancomycin. No linezolid and tigecycline resistant Enterococcus were found. Enterobacteriaceae isolates were highly sensitive to carbapenem. 45.0% of Escherichia coli and 22.9% of Klebsiella pneumoniae isolates were the strains producing extended spectrum-β-lactamases （ESBLs）. Non-fermenting bacteria showed a relatively high resistance to many antimicrobial drugs. Conclusions There are many different kinds of pathogens isolated from blood culture, which showed high resistance to many antimicrobial agents.Clinical doctors should pay great attention to the blood culture and rationally use of antibiotics according to drug susceptibility test result.