ETEST Plazomicin Demonstrates High Accuracy for Enterobacterales Susceptibility Testing
A multicentre evaluation of ETEST plazomicin against broth microdilution for 598 Enterobacterales isolates demonstrated 99.0% essential agreement and 92.8% categorical agreement using FDA breakpoints, with only 1.9% very major errors. The gradient diffusion method offers clinical laboratories an accurate and practical alternative for susceptibility testing of this novel aminoglycoside.
The original study
Multicenter Clinical Evaluation of ETEST Plazomicin (PLZ) for Susceptibility Testing of Enterobacterales.
- Authors
- Blanchard LS, Van Belkum A, Dechaume D, Armstrong TP, Emery CL, Ying YX, et al.
- Journal
- Journal of clinical microbiology
- Type
- Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't
- PMID
- 34757833
Original abstract
Plazomicin (PLZ), brand name ZEMDRI (Cipla Therapeutics), is a novel aminoglycoside antibiotic approved by the U.S. Food and Drug Administration (FDA) for treatment of complicated urinary tract infections including pyelonephritis. ETEST® is a gradient diffusion method that represents an alternative to the more laborious broth micro-dilution (BMD) method for performing antimicrobial susceptibility testing (AST). A multi-center evaluation of the performance of the new ETEST PLZ (bioMérieux) was conducted in comparison with BMD following FDA and International Standards Organization (ISO) recommendations using FDA-defined breakpoints. Clinical isolates of Enterobacterales (n = 598) were included. Fifty-three isolates were resistant to PLZ according to BMD. Overall, the ETEST PLZ demonstrated 99.0% essential agreement (EA), 92.8% category agreement (CA), 1.9% very major errors (VME), 0% major errors (ME), and 7.0% minor errors (mE) with both clinical and challenge isolates of Enterobacterales. The VME was found for a single Serratia marcescens strain. Individual species demonstrated EA rates ≥ 90%. In conclusion, we report that ETEST PLZ represents an accurate tool for performing PLZ AST of Enterobacterales.