Infection and Drug Resistance (Dec 2022)
A Rapid Carbapenemase Genes Detection Method with Xpert Carba-R from Positive Blood Cultures Compared with NG-Test Carba 5 and Sequencing
Abstract
Yuqiao Xu,1,2,* Weijuan Song,1,2,* Peijun Huang,1,2 Yaning Mei,1,2 Yan Zhang,1,2 Ting Xu1,2 1Department of Laboratory Medicine, Jiangsu Province Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, People’s Republic of China; 2Branch of National Clinical Research Center for Laboratory Medicine, Nanjing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yan Zhang; Ting Xu, Department of Laboratory Medicine, Jiangsu Province Hospital, Guangzhou Street No. 300, Nanjing, 210029, People’s Republic of China, Tel +8625-6830-6287, Fax +8625- 8372-4440, Email [email protected]; [email protected]: The objective of the current study was to evaluate the performance of Xpert Carba-R for the direct detection and identification of carbapenemase genes from positive blood cultures.Methods: Pathogens which extracted from positive blood cultures and identified using MALDI-TOF MS as Enterobacterales were included in this study. Xpert Carba-R was used for the rapid detection of carbapenemase genes from positive blood cultures. NG-Test CARBA 5 and polymerase-chain reaction (PCR) sequencing were used for the detection of carbapenemases and carbapenemase genes in positive blood culture isolates, respectively. Finally, antibiotic susceptibility tests were conducted using the VITEK-2 Compact system.Results: A total of 133 positive blood cultures of Enterobacterales were collected and 27 of them were detected to carry carbapenemase genes using Xpert Carba-R. In comparison with PCR sequencing results, the sensitivity and specificity of Xpert Carba-R and NG-Test CARBA 5 were calculated as 100%. Additionally, Xpert Carba-R could significantly shorten the turnaround time by directly detecting positive blood cultures comparing with NG-Test CARBA 5. For 27 carbapenem-producing strains, the resistance rates of carbapenems and aztreonam were 96.3% and 92.6%, respectively. Strains carrying the blaKPC gene were all sensitive to ceftazidime–avibactam. All strains were sensitive to tigecycline and colistin.Conclusion: Xpert Carba-R is suitable for the rapid detection of main carbapenemase genes from positive blood cultures with high sensitivity and specificity. In comparison with NG-Test CARBA 5 and PCR sequencing methods, the timely and convenient method can be a useful test to guide optimal therapy and infection control.Keywords: carbapenemase genes, positive blood culture, rapid detection, Xpert Carba-R
