直接纸片扩散法对阳性血培养的药敏试验诊断价值

Diagnostic value of direct disk diffusion susceptibility test on positive blood culture isolates

目的探讨琼脂纸片扩散法(K-B)直接用于阳性血培养的快速药敏试验的临床价值。方法取Bact/Alert3D120报警阳性血培养标本10mL,经离心处理后,取获得的菌悬液进行K-B纸片法药敏试验,并与Vitek2法鉴定和药敏的标准方法同时进行,比较两种方法的药敏结果差异。结果 325株阳性血培养中,革兰阴性杆菌的药敏结果与Vitek2法符合率是90.3%,严重误差2.4%,主要误差0.9%,次要误差6.3%;革兰阳性球菌的药敏结果与Vitek2法符合率是92.6%,严重误差2.4%,主要误差1.6%,次要误差3.3%。结论革兰阳性球菌的苯唑西林和庆大霉素药敏试验结果,革兰阴性杆菌的头孢呋辛、阿莫西林/克拉维酸、哌拉西林/他唑巴坦的纸片扩散法药敏结果误差较大,K-B纸片扩散法直接用于阳性血培养的快速药敏试验的诊断价值是有限的。

Objective To explore the clinical value of direct disk diffusion susceptibility test on positive blood culture isolates. Methods 10 rnl. aliquots from Bact/Alert3D120 positive culture bottles were centrifuged,then collected suspension to perform direct disk diffusion susceptibility test,processed the samples with Vitek 2 simultaneously, compared susceptibility results with direct disk diffusion method. Results Of 325 positive blood cultures, for 153 gram negative bacilli,there were 90.3~ agreement between two methods,with 2.4% very major,0.9% major, 6.3 ~/00 minor error. For 172 gram-positive cocci, there were 92.6 % agreement between two methods, with 2.4 % very major, 1.6% major,3.3 ~ minor error. Conclusion The high rate of disagreement was observed with oxacillin and gentamicin in gram positive cocci,and with cefuroxime,amoxycillin/clavulanate, piperacillin/tazobatam in gram nega- tive bacilli, the diaRnostic value of direct disk diffusion susceptibility test on positive blood culture isolate is limited.