头孢吡肟对医院分离的革兰阴性杆菌的体外抗菌活性的四种方法学评价

Evaluation of four methods to detect in vitro antimicrobial activity of cefepime for Gram-negative isolates from hospital

目的调查四川大学华西医院2004年9月-11月301株临床常见革兰阴性杆菌对第四代头孢菌素头孢吡肟的耐药状况,评价我院现采用的MICROSCAN细菌鉴定药敏系统中快速接种法的准确性。方法用琼脂稀释法、纸片扩散法、标准浊度法和MICROSCAN快速接种法测定头孢吡肟对301株细菌的体外抑菌活性。以琼脂稀释法为标准参考方法,比较其它三种方法与其一致性。结果琼脂稀释法测定301株革兰阴性杆菌对头孢吡肟的体外总敏感率为78.1%;纸片扩散法、标准浊度法和MICROSCAN快速接种法与标准参考方法的一致率分别为:99.0%、98.3%和95.3%。纸片扩散法、标准浊度法与琼脂稀释法无统计学差异,MICROSCAN快速接种法与琼脂稀释法有统计学差异。结论头孢吡肟对大部分临床常见革兰阴性杆菌具有良好的体外抗菌活性。纸片扩散法及标准浊度法结果准确性较高,我院现采用的MICROSCAN快速接种法的准确性有待进一步探讨。

Objective To investigate the antibiotics resistance pattern to cefepime of Gram-negative bacilli isolated from West China Hospital of Sichuan University during September-November, 2004, and to evaluate the accuracy of prompt inoculation procedure of MICROSCAN Walkaway bacterial identification and susceptibility system. Method We collected 301 Gram-negative isolates and tested the susceptibility of bacteria to cefepime by four methods： Kirby-Bauer （KB） method, standard agar dilution, MICROSCAN turbidity standard method and MICROSCAN prompt method respectively, and compared the consistency of other three method with standard agar dilution method. Result The total susceptibility rate of cefepime was 78. 1% via standard agar dilution method. The consistent rate of KB method, MICROSCAN turbidity standard method and MICROSCAN prompt method to standard agar dilution method was 99.0%, 98.3% and 95. 3% respectively. There were no significant difference between them. Conclusion Cefepime has a powerful in vitro antimlcrobial activity to most clinical Gram-negative bacilli. The accuracy of KB method and MICROSCAN turbidity standard method was vertified. But the accuracy of MICROSCAN prompt method needed the further study.