Related articles in EMJ
Performance of Xpert Carba-R Assay for Identification of Carbapenemase Gene in the Clinical Microbiology Laboratory
Department of Laboratory Medicine, Ewha Womans University College of Medicine, Seoul, 1Sejong Hospital, Bucheon, 2Hankook General Hospital, Seoul, KoreaCorrespondence to:
Ewha Med J 2020; 43(3): 39-42
Published July 31, 2020
Copyright © Ewha Womans University School of Medicine.
Methods: The analytical limit of detection was determined with two suspensions of carbapenemase-producing Enterobacteriaceae (CPE) isolates (KPC and NDM). A total of 52 specimens were evaluated: 21 bacterial isolates from clinical specimens, 21 rectal swabs, and 10 contrived stool specimens.
Results: In bacterial isolates, concordant results between the Xpert Carba-R Assay and PCR were found in 20 of 21; 8 KPC, 8 NDM, 1 IMP, and 2 multiple carbapenamase genes (KPC/NDM, NDM/OXA) were detected both by Xpert Carba-R Assay and PCR. In one GES-positive isolate, Xpert Carba-R Assay showed a negative result as expected. One VIM-positive isolate tested negative by Xpert Carba-R Assay. Complete concordance was seen in rectal swab specimens: 4 specimens with KPC and 17 specimens with negative results both by Xpert Carba-R Assay and surveillance culture. Among the 10 contrived stool specimens, Xpert Carba-R Assay detected carbapenemase genes in 9 specimens as expected according to the CPE strains spiked into the contrived stool; 2 KPC, 4 NDM, 1 IMP, and 2 multiple carabapenamase genes (NDM/KPC, NDM/OXA). One VIM-positive specimen tested negative by Xpert Carba-R Assay.
Conclusion: In conclusion, the Xpert Carba-R Assay can be used to identify carbapenemase gene in bacterial isolates cultured from clinical specimens and detect CPE carrier using rectal swab in clinical laboratories.