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bioRxiv · 10.1101/842963

A highly multiplexed melt-curve assay for detecting the most prevalent carbapenemase, ESBL and AmpC genes

Edwards, T.·Williams, C.·Teethaisong, Y.·Sealey, J.·Sasaki, S.·Hobbs, G.·Cuevas, L.·Evans, K.·Adams, E.
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Abstract

Resistance to third generation cephalosporins and carbapenems in Gram-negative bacteria is chiefly mediated by beta-lactamases including ESBL, AmpC and carbapenemase enzymes. Routine phenotypic detection methods do not provide timely results, and there is a lack of comprehensive molecular panels covering all important markers. An ESBL/carbapenemase HRM assay (SHV, TEM, CTX-M ESBLs, and NDM, IMP, KPC, VIM and OXA-48-like carbapenemases) and an AmpC HRM assay (16S rDNA control, FOX, MOX, ACC, EBC, CIT and DHA) were designed, and evaluated on 111 Gram-negative isolates with mixed resistance patterns. The sensitivity for carbapenemase, ESBL and AmpC genes was 96.7% (95%CI:82.8-99.9%), 93.6% (95%CI:85.7-97.9%) and 93.8% (95%CI:82.8-98.7%), respectively with a specificity of 100% (95%CI:95.6-100%), 93.9% (95%CI:79.8-99.3%) and 93.7% (95%CI:84.5-98.2%). The HRM assays enable the simultaneous detection of the fourteen most important ESBL, carbapenemase and AmpC genes and could be used as a molecular surveillance tool or to hasten detection of AMR for treatment management.

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Edwards, T., Williams, C., Teethaisong, Y., Sealey, J., Sasaki, S., Hobbs, G., Cuevas, L., Evans, K., Adams, E.. 2019-11-15. A highly multiplexed melt-curve assay for detecting the most prevalent carbapenemase, ESBL and AmpC genes. https://doi.org/10.1101/842963

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