K-B法对自动化检测流感嗜血杆菌对氨苄西林药敏误差的校正作用

摘要

Objective Broth dilution method was used as a reference method to observe the capability of Kirby-Bauer disc diffusion assay(K-B)for correcting automated ampicillin susceptibility detection of He-mophilus influenzae(HI).Methods A total of 228 HI strains isolated were collected,broth dilution assay,K-B and automated microdilution broth test(ATB)were used to determine the susceptibility of HI to ampicillin. Analyze the essential agreements of the three methods and the correction of K-B to the errors of A TB. Results The essential agreement of K-B or ATB with broth dilution method were 77.19%,70.18% respec-tively,combination of K-B and ATB could make the essential agreement increase up to 86.0%,which was sig-nificantly higher than ATB(χ2=16.600,P=0.000).Major error of ATB(42.0%)was higher than that of K-B(10.0%)(χ2=13.306,P=0.001),but very major error and minor error showed no significant difference be-tween the two methods(χ2=1.208,P=0.272;χ2=1.182,P=0.227),meanwhile,76.19% of major error of ATB could be corrected by K-B.For the very major error of ATB,53.57% could be corrected by K-B.Howev-er,the corrective capability of K-B to minor error of ATB was relative low.Conclusion K-B test could correct some errors generated by ATB.For the β-lactamase negative strains which were judged as ampicillin resistance by A TB,K-B test should be used to correct the errors by ATB.Moreover,it is necessary to apply K-B to confirm am-picillin sensitivity of the β-lactamase positive strains which were judged as ampicillin susceptible by ATB.%目的 以肉汤稀释法为参考方法,观察纸片扩散(K-B)法对自动化微量肉汤稀释(A TB)法产生误差的校正作用.方法 收集228株流感嗜血杆菌(HI),采用肉汤稀释法、K-B法、A TB法同时检测 HI对氨苄西林的敏感性,观察3种实验方法药敏结果的一致性,分析K-B法对A TB法产生误差的校正作用.结果 K-B法和A TB法与肉汤稀释法的一致率分别为77.19%、70.18%,二者联合可将一致率提高至86.0%,明显高于A TB法(χ2=16.600,P=0.000);A TB法的重大误差率(42.0%)明显高于K-B法(10.0%,χ2=13.306,P=0.001),K-B法与 A TB法的次要误差率和极重大误差率差异均无统计学意义(χ2=1.208,P=0.272;χ2=1.182,P=0.227);K-B法可校正A TB法76.19% 的重大误差和53.57% 的极重大误差,K-B法对A TB法次要误差的校正能力较弱.结论 K-B法可合理校正A TB法产生的药敏误差,A TB法判定为氨苄西林耐药且β-内酰胺酶阴性菌株的菌株,建议采用K-B法进行校正,而A TB法判定为氨苄西林敏感且β-内酰胺酶阳性的菌株,则务必采用K-B法进行校正.