血培养常见病原菌分布及耐药性分析

Distribution and drug resistance of pathogens from blood culture samples

目的分析医院血流感染病原菌的分布特点及耐药性变迁,为临床抗感染的预防与控制提供实验室依据。方法采用自动血培养仪BD9240对血培养瓶进行连续培养监测,全自动微生物分析系统对血标本中分离的病原菌进行鉴定和药敏试验,结果判定按照CLSI 2008标准。结果 2005-2011年共分离病原菌2 762株,其中革兰阳性菌1 296株占47.0%、革兰阴性菌1 387株占50.2%、真菌79株占2.8%;在2 762株非重复分离病原菌中,主要为凝固酶阴性葡萄球菌、大肠埃希菌、肺炎克雷伯菌、金黄色葡萄球菌、肠球菌属、铜绿假单胞菌及鲍氏不动杆菌分别占25.92%、20.06%、9.67%、8.73%、7.49%、4.85%及3.33%;产超广谱β-内酰胺酶大肠埃希菌、肺炎克雷伯菌检出率分别为43.8%和24.3%;肠杆菌科细菌对碳青霉烯类抗菌药物仍保持100.00%敏感;耐甲氧西林金黄色葡萄球菌和耐甲氧西林凝固酶阴性葡萄球菌的检出率分别为56.00%占金黄色葡萄球菌和90.80%占凝固酶阴性葡萄球菌,未发现耐万古霉素葡萄球菌;检出11株耐万古霉素屎肠球菌,耐药率为8.03%;大肠埃希菌、肺炎克雷伯菌对亚胺培南、美罗培南耐药率<1.00%,铜绿假单胞菌对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦耐药率<8.00%。结论医院血流感染病原菌主要为凝固酶阴性葡萄球菌,其次是大肠埃希菌和肺炎克雷伯菌,万古霉素、利奈唑胺、替加环素对革兰阳性球菌有较好的抗菌活性,碳青霉烯类及头孢哌酮/舒巴坦对革兰阴性杆菌有较好的抗菌活性。

OBJECTIVE To analyze the characteristics of distribution and drug resistance of pathogens isolated from bloodstream infections in the hospital,and to provide the laboratory basis for clinical treatment and infection control.METHODS The blood culture bottle was continuously cultured and monitored in BD BACTEC9240.The bacterial identification and drug susceptibility testing were carried out in the pathogens isolated from blood samples by automatic bacteria identification system..The results were determined by the CLSI standard of 2008edition. RESULTS From Jan.2005to Dec.2011,2762strains of pathogens were isolated,including 1296strains of grampositive bacteria（47.0%）,1387strains of gram-negative bacteria（50.2%）and 79strains of fungi（2.8%）.Among 2762strains of no repeating pathogens isolated,the coagulase-negative Staphylococcus accounted for 25.92%,followed by Escherichia coli（20.06%）,Klebsiella pneumonia（9.67%）,S.aureus（8.73%）,Enterococcus（7.49%）, Pseudomonas aeruginosa（4.85%）,Acinetobacter baumannnii（3.33%）.The detection rates of ESBLs of E.coli and K.pneumonia were 43.8% and 24.3%,respectively;Enterobacteriaceae were 100% sensitive to carbapenems;the detection rates of MRSA and MRCNS were 56.00%according to Staphylococcus and 90.8%according to coagulase-negative Staphylococcus,respectively.11stains of vancomycin-resistant Enterococcus faecium were detected,and the drug resistance rate was 8.03%.The drug resistance rates of E.coli,K.pneumoniato imipenem and meropenem were1.00%,and the drug resistance rates of P.aeruginosato cefoperazone/sulbactam,piperacillin/tazobactam were less than 8.00%.CONCLUSIONIn our hospital,the most common BSI-causing pathogens are coagulase-negative Staphylococcus,followed by E.coli and Klebsiella pneumonia.vancomcin,linezolid, and tigecycline show favorable antibacterial activity against gram-positive cocci,as do carbapenems and cefoperazone/sulbactam against gram-negative bacilli.