Simple jQuery Dropdowns
Please use this identifier to cite or link to this item:
Title: ChloS-HRM, a novel assay to identify chloramphenicol-susceptible Escherichia coli and Klebsiella pneumoniae in Malawi
Authors: Christopher T. Williams
Patrick Musicha
Nicholas A. Feasey
Emily R. Adams
Thomas Edwards
Queen Elizabeth Central Hospital Malawi
Liverpool School of Tropical Medicine
Mahidol University
Nuffield Department of Clinical Medicine
Keywords: Medicine
Issue Date: 1-Jan-2019
Citation: Journal of Antimicrobial Chemotherapy. Vol.74, No.5 (2019), 1212-1217
Abstract: © 2019 The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. Objectives: Chloramphenicol is a broad-spectrum antimicrobial widely available in sub-Saharan Africa. With susceptibility re-emerging among Enterobacteriaceae in Blantyre, Malawi, we designed and evaluated a new high-resolution melt (HRM) RT-PCR assay, ChloS-HRM, to identify chloramphenicol-susceptible infections in a hospital setting. Methods: Seventy-two previously whole-genome sequenced isolates of Escherichia coli and Klebsiella pneumoniae from the Queen Elizabeth Central Hospital, Malawi, were subjected to determination of chloramphenicol MICs. Primers were designed to detect 18 chloramphenicol resistance genes that produce seven distinct peaks correlating with different gene groups (catA1, catA2, catA3, catB2, catB group 3, cmlA and floR) following HRM analysis. ChloS-HRM results were compared with MIC and WGS results. Results: ChloS-HRM correctly identified 15 of 17 phenotypically susceptible isolates and 54 of 55 resistant isolates, giving an accuracy of 88% in identifying susceptibility and 98% in identifying resistance. WGS identified 16 of 17 susceptible and 54 of 55 resistant isolates, giving an accuracy of 94% in identifying susceptibility and 98% in identifying resistance. The single false-susceptible result had no detectable gene by ChloS-HRM or WGS. Compared with WGS, ChloS-HRM had 100% sensitivity and specificity for catA (catA1-3), cmlA and floR, and 96% specificity for catB; sensitivity could not be estimated due to the lack of catB in the clinical sample collection. The overall agreement between MIC and HRM was 96% and between MIC and WGS it was 97%. Conclusions: ChloS-HRM could support antimicrobial stewardship in enabling de-escalation from third-generation cephalosporins by identifying chloramphenicol-susceptible infections. This would be valuable in areas with chloramphenicol-susceptible MDR and XDR Enterobacteriaceae.
ISSN: 14602091
Appears in Collections:Scopus 2019

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.