下呼吸道感染病原菌鉴定与耐药性分析

Identification of pathogenic bacteria causing lower respiratory tract infection and drug resistance

目的了解医院下呼吸道感染病原菌的现状和体外耐药性,分析产超广谱β-内酰胺酶(ESBLs)的产生情况,为临床的合理用药提供参考。方法采用全自动微生物鉴定仪对从门诊和住院下呼吸道感染患者痰标本中分离的病原菌进行鉴定及药物敏感试验,并用双纸片扩散法对产ESBLs菌株进行确证。结果共检出684株病原菌,革兰阴性杆菌占主导地位(62.1%);产ESBLs大肠埃希菌检出率为53.6%,肺炎克雷伯的检出率为34.3%;革兰阳性球菌对万古霉素全部敏感,革兰阴性杆菌对亚胺培南的耐药率较低,对酶抑制剂类抗菌药物较敏感,对第一、二代头孢菌素耐药率较高。结论随着抗菌药物的持续使用,呼吸道感染的产ESBLs大肠埃希菌耐药情况日趋严重,耐药性监测对临床合理应用抗菌药物具有指导意义。

OBJECTIVE To investigate the clinical characteristic and antimicrobial resistance of pathogenic bacteria causing lower respiratory tract infection, in order to provide reference for the clinical application of drugs. METHODS The strains of pathogenic bacteria were detected and their sensitivity to antibiotics was determined by Walkway 40 automatic bacterium identifying and drug sensitivity analyzing systems, then the specimens in which bacteria was detected and the result of sensitivity to antibiotics were analyzed, and the extended spectrum β- lactamase （ESBLs） were identified by means of disc agar diffusion method. RESULTS All 684 pathogenic bacteria strain were detected, among which Gram-positive cocci accounted for 27.6%, Gram-negative bacteria accounted for 62.1%, and fungus accounted for 10.2%. Among the isolated 37 strains ESBLs producing Escherichia coli （53.6%） and Klebsiella pneumoniae （34. 3%）. Gram-positive cocci were all sensitive to vancomyein. The resistant rate of Gram-negative bacteria to IMP and complex antibiotics containing β-lactamases inhibitor were relatively low, while the resistant rate to other antimicrobial drugs was higher. CONCLUSION The drug resistance of ESBLs-producing E. coli is increasing with the consecutive application of antibiotics. It is very important to rationally use drugs for clinical treatment of the infections according to the results of antibiotics susceptibility tests.