Multicenter evaluation of the Xpert Carba-R assay for detection and identification of carbapenemase genes in sputum specimens Journal Article
| Authors: | Cai, Z.; Tao, J.; Jia, T.; Fu, H.; Zhang, X.; Zhao, M.; Du, H.; Yu, H.; Shan, B.; Huang, B.; Chen, L.; Tang, Y. W.; Jia, W.; Qu, F. |
| Article Title: | Multicenter evaluation of the Xpert Carba-R assay for detection and identification of carbapenemase genes in sputum specimens |
| Abstract: | Rapid diagnosis of infections caused by carbapenem-resistant Enterobacteriaceae (CRE) is crucial for proper treatment and infection control. The Xpert Carba-R assay is a qualitative multiplex real-time PCR method that qualitatively detects and differentiates five common carbapenemase genes (blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP) directly from rectal swabs or purified colonies within approximately 1 h. We performed a multicenter evaluation of the investigational use of the Carba-R assay for detection and differentiation of carbapenemase genes from sputum specimens in patients with a clinical diagnosis of pneumonia. The intra- and interassay coefficients of variation values for the Carba-R assay were 0.2% to 2.0% and 1.4% to 2.3%, respectively. A total of 301 sputum specimens were collected and tested. Compared to bacterial culture followed by PCR identification of resistance genes from colonies, the Carba-R assay reduced turnaround time from 56 to 84 h to less than 2 h. Carbapenemase genes were detected by the Carba-R assay in Klebsiella pneumoniae (n=236), Escherichia coli (n=22), Enterobacter cloacae (n=23), Klebsiella oxytoca (n=8), Serratia marcescens (n=6), Citrobacter freundii (n=4), and Klebsiella aerogenes (n=2). The Carba-R assay detected 112 blaKPC (33.5%), 70 blaNDM (21.0%), 8 blaIMP (2.4%), and 2 blaVIM (0.6%) genes, with positive percent agreement, negative percent agreement, and concordance rates of 92.9%, 86.7%, and 88.3%, respectively, for the dominant blaKPC and 85.0%, 87.8%, and 87.4%, respectively, for the blaNDM genes. Neither method detected the blaOXA-48 carbapenemase gene. The convenient, rapid, and simple characteristics of the Xpert Carba-R assay make it a potential tool for CRE detection and identification directly in sputum specimens. © 2020 American Society for Microbiology. |
| Keywords: | sputum; carbapenem-resistant enterobacteriaceae; blakpc; blandm; carba-r assay |
| Journal Title: | Journal of Clinical Microbiology |
| Volume: | 58 |
| Issue: | 9 |
| ISSN: | 0095-1137 |
| Publisher: | American Society for Microbiology |
| Date Published: | 2020-09-01 |
| Start Page: | e00644-20 |
| Language: | English |
| DOI: | 10.1128/jcm.00644-20 |
| PUBMED: | 32522829 |
| PROVIDER: | scopus |
| PMCID: | PMC7448655 |
| DOI/URL: | |
| Notes: | Article -- Source: Scopus |
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