耐碳青霉烯肺炎克雷伯菌对头孢他啶/阿维巴坦敏感性及不同检测方法差异性研究

Sensitivity of carbapenem - resistant Klebsiella pneumoniae to ceftazidime / avibactam and susceptibility differences in different detection methods

目的 了解耐碳青霉烯类肺炎克雷伯菌(CRKP)对头孢他啶/阿维巴坦敏感性以及不同方法检测存在的差异,为实验室药敏检测和临床抗菌药物的使用提供依据。方法 选择2019年—2021年临床分离的耐碳青霉烯肺炎克雷伯菌150株,分别采用微量肉汤稀释法、E-test法和纸片(K-B)法检测头孢他啶/阿维巴坦体外的敏感性,分析3种药敏检测方法所存在的差异。结果 微量肉汤稀释法和E-test法检测CRKP对头孢他啶/阿维巴坦的敏感率分别为68.0%和67.3%;E-test法检测的MIC值高于标准方法,差异有统计学意义(P<0.01);E-test法和K-B法的方法学误差分析均在标准范围内;以微量肉汤稀释法为参考标准,K-B法测得头孢他啶/阿维巴坦抑菌圈为20 mm的MIC值为4.00μg/ml, CA值为0.0%,低于标准参考值;K-B法抑菌圈直径KB值与微量肉汤稀释法MIC值之间方差分析,KB值与MIC值存在线性关系,回归方程为y=-21x+496.62,r2=0.617,P<0.01。结论 本地区CRKP菌株对于头孢他啶/阿维巴坦具有较高的敏感性,E-test相对参考方法具有较高的一致性和准确性,适合在临床实验室推广。

Objective This study aims to understand the sensitivity of carbapenem-resistant Klebsiella pneumoniae to ceftazi⁃dime/avibactam and the sensitivity differences in different methods,so as to provide evidence for laboratory drug susceptibility test and clinical antimicrobial use.Methods A total of 150 carbapenem-resistant Klebsiella pneumoniae isolates isolated from 2019 to 2021 were selected for their detection of in vitro sensitivity to ceftazidime/avibartam by microbroth dilution,E-test method and disk(K-B)method,respectively,and the differences among the three methods were also analyzed.Results The sensitivity rates of CRKP to ceftazidime/avibactam were 68.0%and 67.3%by micro-broth dilution method and E-test method,respectively.The MIC median value detected by the E-test method was significantly higher than that of the standard method,with the difference statistically significant(P<0.01).The methodological errors of E-test method and K-B method are within the standard range.Using microbroth dilution method as the reference standard,the MIC value to ceftazidme/avibac⁃tam was 4.00μg/ml and the CA value was 0.0%when the bacteriostasis zone was 20 mm by K-B method,which is lower than the standard reference value.The variance analysis on KB value of antibacterial zone diameter in K-B method and MIC value in microbroth dilution method showed that there was a linear relationship between KB value and MIC value,and the regression equation was y=-21x+496.62,r2=0.617,P<0.01.Conclusion The CRKP strains in this region have high sensitivity to ceftazidime/avibactam,and E-test has high consistency and accuracy relative to the reference method,which is suitable for the promotion in clinical laboratories.