纸片扩散法检测淋病奈瑟菌对头孢菌素类药物敏感性的准确率分析

Evaluation of Kirby-Bauer method for cephalosporin susceptibility in Neisseria gonorrhoeae

目的评价纸片扩散法(K-B法)检测淋病奈瑟菌对两种第三代头孢菌素类药物敏感性的准确率。方法在广西部分地区性病科门诊收集了262株淋病奈瑟菌菌株,采用K-B法和琼脂稀释法检测淋病奈瑟菌对头孢曲松和头孢克肟两种药物的敏感性。结果 K-B法和琼脂稀释法对头孢曲松敏感菌株的检测率分别为93.1%和100%,对头孢克肟敏感菌株的检测率分别为90.8%和99.2%。K-B法检测了244株菌株对头孢曲松药物的敏感性,与琼脂稀释法检测的最小抑菌浓度结果一致,发现18株敏感菌株被误判为非敏感菌株;K-B法检测出238株菌株对头孢克肟药物敏感,其中236株菌株与琼脂稀释法检测最小抑菌浓度结果一致,24株敏感菌株误判为非敏感菌株,有2株非敏感菌株被误判为敏感菌株。K-B法对两种头孢菌素类药物敏感菌株的检测率与琼脂稀释法检测结果差异有统计学意义。结论在应用于临床时应注意其应用范围,如遇到K-B法敏感结果时可直接指导临床用药,但当K-B法结果出现非敏感时,应采用琼脂稀释法来最终判定其敏感性。

Objective To evaluate accuracy of K-B method for detection of Neisseria gonorrhoeae sensitivity to two kinds of the third-generation cephalosporins. Methods 262 Neisseria gonorrhoeae strains were collected from the STD clinic outpatients in Guangxi,and sensitivity of ceftriaxone and cefiximewere detected by K-B method and agar dilution method. Results The detection rate of ceftriaxone susceptible strains by K-B method and agar dilu- tion method were 93.1% and 100 % respectively, and that of cefixime were 90.8% and 99.2 %. 244 strains detected by K-B method were sensitive to ceftriaxone agents, consistent with the MIC results detected by agar dilution meth- od. It was found that 18 sensitive strains were misclassified as non-susceptible strains. 238 strains of cefiximewere detected by K-B method in drug sensitivity, of which 236 strains were consistent with MIC detection results by agar dilution. Among them, there were 24 sensitive strains misjudged as non-sensitive strains, and 2 non-sensitive strains were mistaken as sensitive strains. Conclusion There are significant differences between the two methods to detect- two kinds of cephalosporins sensitive strains. It is suggested to pay attention to the clinical practice of K-B method for Neisseria gonorrhoeae. K-B susceptible results may directly guide clinical medication and the resistant results should be determined by the results of alzar dilution method.