血流感染病原菌分布及耐药特性分析

目的了解血流感染主要病原菌的分布特点及对常用抗菌药物的耐药情况,以指导临床合理用药。方法对2006年1月—2011年6月期间本院临床各科室送检的血培养标本采用美国Bactec9120全自动血培养仪进行培养,Vitek-32型仪进行菌种鉴定,纸片扩散法测定菌株对抗菌药物的敏感性,头孢西丁法检测耐甲氧西林葡菌球菌,WHONET5.6软件分析数据。结果共分离出598株病原菌,其中革兰阳性球菌282株,占47.2%;革兰阴性杆菌289株,占48.3%,真菌15株,占2.5%。最常见的感染菌分别为大肠埃希菌、表皮葡萄球菌、肺炎克雷伯菌、金黄色葡萄球菌、铜绿假单胞菌及鲍曼不动杆菌。金黄色葡萄球菌和表皮葡萄球菌中耐甲氧西林葡萄球菌检出率分别为63.9%和87.9%,其对青霉素耐药率均>95.0%,均未发现对万古霉素和替考拉宁耐药株。大肠埃希菌和肺炎克雷伯菌对碳青霉烯类抗生素耐药率最低,对氨苄西林耐药率分别为93.8%和100%。铜绿假单胞菌对亚胺培南耐药率为16.7%,而鲍曼不动杆菌对亚胺培南耐药率高达63.6%,鲍曼不动杆菌对其他抗菌药物的耐药率均>60%。结论本单位血流感染以大肠埃希菌和葡萄球菌为主。表皮葡萄球菌较金黄色葡萄球菌耐药性严重,非发酵菌比肠杆菌科细菌耐药性严重,尤其是鲍曼不动杆菌引起的血流感染无经验抗菌药物可选,必须在药敏试验指导下用药。

The distribution and resistance characteristics analysis of pathogens from bloodstream infection

Objective To investigate bacteria distribution characteristic and antimicrobial drug resistance of main pathogens of bloodstream infection in our hospital,and to guide the clinical treatment.Methods Various clinical departments blood cultures samples which were collected from January 2006 to June 2011 in the Second Affiliated Hospital of Nanchang University were incubated by Bactec9120 automated blood culture and identified by Vitek-32 automated microbial identified.Antimicrobial susceptibility testing was determined by disc agar diffusion method.Methicillin-resistant Staphylococcus(MRS) was detected by cefoxitin method.The antimicrobial susceptibility data was analyzed by WHONET 5.6 Software.Results 598 strains were isolated from blood culture,The isolates included 282 strains from Gram-positive cocci(47.2%),289 strains from Gram-negative bacilli(48.3%),15 strains from fungi(2.5%).The Escherichia coli,Staphylococcus epidermidis,Klebsiella pneumoniae,Staphylococcus aureus,Pseudomonas aeruginosa and Acinetobacter baumannii are the main pathogenic bacterium in our hospital. The detection rate of methicillin-resistant Staphylococcus(MRS) from Staphylococcus aureus and Staphylococcus epidermidis were 63.9%and 87.9%,respectively.The resistance rates of Staphylococcus aureus and Staphylococcus epidermidis to penicillin were more than 95%and all strains were sensitive to vancomycin and teicoplanin.The Escherichia coli and Klebsiella pneumoniae were most sensitive to carbapenems antibiotics,the resistance rates of Escherichia coli and Klebsiella pneumoniae to ampicillin were 93.8%and 100%respectively.The resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to imipenem were 16.7%and 63.6%respectively.The resistant rates of Acinetobacter baumannii to other testing drugs were more than 60%.Conclusion The Escherichia coli and Staphylococcus were the main pathogenic bacterium in our hospital.The resistance rate of Staphylococcus aureus is lower than Staphylococcus epidermidis.The drug resistance of non-fermenting bacteria is higher than Enterobacteriaceae bacteria.Especially,there was no optional antimicrobial agents for bloodstream infections caused by Acinetobacter baumannii.Therefore,in the selection of antimicrobial agents in the treatment of pathogens,doctors should refer to the results of bacterial resistant surveillance.