目的 评估Xpert Carba-R平台在血培养碳青霉烯耐药基因的快速检测中的应用价值。 方法 本研究选取16株携带不同碳青霉烯耐药基因型的肠杆菌目菌株制备模拟阳性血培养样本，采用Xpert Carba-R直接检测模拟血培养液中的碳青霉烯耐药基因。收集2022年1—6月南京医科大学第一附属医院临床血培养鉴定为肠杆菌目的样本117份进行前瞻性研究，采用Xpert Carba-R检测5种碳青霉烯耐药基因，以PCR测序法为参考方法评价其灵敏度与特异性。同时收集阳性患者临床资料进行预后分析。 结果 16份制备的模拟阳性血培养样本采用Xpert Carba-R检出bla KPC阳性8份，bla NDM阳性5份，bla IMP阳性1份，阴性2份，与已知结果完全一致。117份临床血培养阳性样本中28份经Xpert Carba-R检出为碳青霉烯耐药基因阳性，其中bla KPC阳性24份，bla NDM 2份，bla KPC+bla NDM 2份，与PCR测序法相比其敏感度和特异度均为100%，且检测用时明显减少。25例患者中9例采用单药治疗，5例治疗有效；16例采用联合治疗，12例治疗有效；共17例治疗有效，8例治疗无效其中3例死亡，病死率为12%（3/25）。 结论 Xpert Carba-R可快速、准确地检测血培养液中碳青霉烯耐药基因，为临床早期合理用药提供依据。 This work aims to evaluate a rapid detection method of carbapenem resistance genes in blood cultures based on Xpert Carba-R and preliminarily evaluate its clinical application. Methods Sixteen strains of Enterobacterales carrying different carbapenem resistance genes were selected to prepare simulated positive blood culture samples and Xpert Carba-R was used to directly detect carbapenem resistance genes in the simulated positive blood culture. From January 2022 to June, a prospective study was conducted on a total of 117 Enterobacteriaceae-positive blood culture samples in the First Affiliated Hospital of Nanjing Medical University. Xpert Carba-R, detecting five kinds of carbapenem resistance genes in these samples, was evaluated in sensitivity and specificity compared to polymerase chain reaction sequencing. Meanwhile clinical data of positive patients was collected for prognostic analysis. Results Of the 16 simulated specimens, 14 strains had carbapenem resistance genes detected by Xpert Carba-R, including 8 bla KPC, 5 bla NDM and 1 bla IMP, showing 100% agreement with the known results. As of the 117 clinical specimens, 28 cases were determined to be Enterobacterales harboring carbapenem resistance genes, including 24 bla KPC, 2 bla NDM and 2 bla KPC+bla NDM. In comparison to the PCR sequencing, the sensitivity and specificity of Xpert Carba-R were both 100% for blood culture samples, and furthermore, the detection time was significantly reduced. Of the 25 positive patients, 9 cases were treated with monotherapy and 5 cases were effective, other 16 cases received combined treatment and 12 cases were effective. A total of 17 cases were effective, 8 cases were ineffective and 3 of them died, the mortality rate was 12% (3/25). Conclusion Xpert Carba-R can rapidly and accurately detect carbapenem resistance genes in blood culture, which can provide evidence for rational drug therapy in early clinical stage.
Clinical application and evaluation of rapid detection of carbapenem resistance genes in blood cultures by Xpert Carba-R
This work aims to evaluate a rapid detection method of carbapenem resistance genes in blood cultures based on Xpert Carba-R and preliminarily evaluate its clinical application. Methods Sixteen strains of Enterobacterales carrying different carbapenem resistance genes were selected to prepare simulated positive blood culture samples and Xpert Carba-R was used to directly detect carbapenem resistance genes in the simulated positive blood culture. From January 2022 to June, a prospective study was conducted on a total of 117 Enterobacteriaceae-positive blood culture samples in the First Affiliated Hospital of Nanjing Medical University. Xpert Carba-R, detecting five kinds of carbapenem resistance genes in these samples, was evaluated in sensitivity and specificity compared to polymerase chain reaction sequencing. Meanwhile clinical data of positive patients was collected for prognostic analysis. Results Of the 16 simulated specimens, 14 strains had carbapenem resistance genes detected by Xpert Carba-R, including 8 bla KPC, 5 bla NDM and 1 bla IMP, showing 100% agreement with the known results. As of the 117 clinical specimens, 28 cases were determined to be Enterobacterales harboring carbapenem resistance genes, including 24 bla KPC, 2 bla NDM and 2 bla KPC+bla NDM. In comparison to the PCR sequencing, the sensitivity and specificity of Xpert Carba-R were both 100% for blood culture samples, and furthermore, the detection time was significantly reduced. Of the 25 positive patients, 9 cases were treated with monotherapy and 5 cases were effective, other 16 cases received combined treatment and 12 cases were effective. A total of 17 cases were effective, 8 cases were ineffective and 3 of them died, the mortality rate was 12% (3/25). Conclusion Xpert Carba-R can rapidly and accurately detect carbapenem resistance genes in blood culture, which can provide evidence for rational drug therapy in early clinical stage.
Drug resistance, microbialCarbapenemsDrug-resistance geneBlood cultureRapid detection
万方数据
