头孢吡肟对革兰阴性杆菌的体外敏感性分析及方法评价

Evaluation of Detecting Methods and in Vitro Antimicrobial Activity of Cefepime to Gram-Negative Isolates from Hospital

目的调查昆明医学院第一附属医院2007年8月至12月301株临床常见革兰阴性杆菌对第4代头孢菌素头孢吡肟的耐药状况,评价采用的MICROSCAN细菌鉴定药物敏感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,比较其他3种方法与其结果的一致性。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78.07%;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99.00%,98.34%和95.35%。纸片扩散法、标准浊度法检查结果与琼脂稀释法无统计学差异(P>0.05),MICROSCAN快速接种法检查结果与琼脂稀释法有统计学差异(P<0.05)。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,MICROSCAN快速接种法的准确性有待进一步探讨。

Objective To investigate the antibiotic resistance pattern of Gram negative bacilli to cefepime, which were isolated from the First Affiliated Hospital of Kunming Medical College during August-December 2007, and to evaluate the accuracy of prompt inoculation procedure of Microscan Walkaway bacterial identification and susceptibility system. Methods 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. Results 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 antimicrobial activity to most clinical Gram negative bacilli. The accuracy of KB method and Microscan turbidity standard method was higher. But the accuracy of Microscan prompt method needs the further study.