下呼吸道感染病原菌分布及耐药性分析

Distribution and drug resistance of pathogens causing lower respiratory tract infections

目的通过检测住院患者经支气管肺泡灌洗培养细菌的分布及耐药特征,指导临床合理应用抗菌药物。方法采用MicroScanAutoScan-40半自动微生物鉴定仪和药敏系统及配套进行菌株鉴定与药物敏感性测定,并检测产超广谱β-内酰胺酶(ESBLs)及耐甲氧西林金黄色葡萄球菌(MRSA),采用WHONET5软件进行数据统计分析。结果共检出849株病原菌,革兰阴性杆菌793株占93.4%;革兰阳性球菌56株占6.6%,均为金黄色葡萄球菌,主要革兰阴性杆菌依次为铜绿假单胞菌、鲍氏不动杆菌、肺炎克雷伯菌、大肠埃希菌、嗜麦芽寡养单胞菌,分别占32.0%、23.4%、15.6%、13.6%、8.8%;产ESBLs大肠埃希菌和肺炎克雷伯菌的检出率分别为48.7%和34.1%,MRSA检出率为32.1%;对铜绿假单胞菌耐药率<20.0%的抗菌药物有阿米卡星、妥布霉素及哌拉西林/他唑巴坦,鲍氏不动杆菌对亚胺培南耐药率最低,为12.0%,肺炎克雷伯菌对亚胺培南耐药率为1.5%,大肠埃希菌对哌拉西林/他唑巴坦、阿米卡星、亚胺培南耐药率较低,分别为6.1%、17.4%、0,嗜麦芽寡养单胞菌对左氧氟沙星耐药率为13.3%,金黄色葡萄球菌对万古霉素100.0%敏感。结论医院获得性下呼吸道感染以革兰阴性菌为主,临床应重视病原学检查及根据药敏合理选择应用抗菌药物,以减少病原菌耐药的发生。

OBJECTIVE To investigate the antibiotic resistance and distribution of the lower respiratory tract infection pathogens cultured from bronchoalveolar lavage so as to guide the reasonable clinical use of antibiotics.METHODS The bacterial identification and antibiotic susceptibility testings were carried out by using MicroScan AutoScan-40 system,and the ESBLs and MRSA were detected;the data were analyzed by WHONET 5.0 software.RESULTS Of totally 849 strains of pathogens isolated,there were 793（93.4%）strains of gram-negative bacilli and 56（6.6%）strains of gram-positive cocci;The main species of gram-negative bacilli included the Pseudomonas aeruginosa（32.0%）,Acinetobacter baumannii（23.4%）,Klebsiella pneumoniae（15.6%）,Escherichia coli（13.6%） and Stenotrophomonas maltophilia（8.8%）.There were extended spectrumβ-lactamases（ESBLs）produced by E.coli（48.7%）and K.pneumoniae strains（34.1%）.The ratio of MRSA was 32.1%.The drug resistance rates of the P.aeruginosato amikacin,tobramycin and piperacillin/tazobactam were below 20.0%;the drug resistance rate of the A.baumannii to imipenem was the lowest（12.0%）;the drug resistance rate of the K.pneumoniae to imipenem was 1.5%;the drug resistance rates of the E.coli to imipenem,amikacin and piperacillin/ tazobactam were 6.1%,17.4%,and 0,respectively the drug resistance rate of Stenotrophomonas maltophiliato levofloxacin was 13.3%;the Staphylococcus aureus strains were 100.0% sensitive to vancomycin.CONCLUSIONThe gram-negative bacilli are the predominant pathogens causing the hospital-acquired lower respiratory tract infections;it is necessary for the hospital to pay attention to the etiological examination and to choose antibiotics based on the drug susceptibility testing so as to reduce the drug resistance of pathogens.