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Updated: Jul 5, 2026
08:57
Amplicon Sequencing using the Long-Read Sequencing Technologies
Published on: August 29, 2025
Molecular characterisation of linezolid resistance in two vancomycin-resistant (VanB) Enterococcus faecium isolates
B Saager1, H Rohde, B S Timmerbeil
1Department of Pharmaceutical Biology and Microbiology, University of Hamburg, Bundesstrasse 45, Hamburg, Germany.
Summary
This study details vancomycin-resistant, linezolid-resistant Enterococcus faecium. Pyrosequencing identified a specific mutation linked to linezolid resistance, which can dynamically revert, aiding resistance monitoring.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Enterococcus faecium is a significant cause of hospital-acquired infections.
- Vancomycin resistance (VanB) and linezolid resistance are growing clinical concerns.
- Understanding the molecular basis of linezolid resistance is crucial for effective treatment.
Observation:
- Two clinically relevant Enterococcus faecium isolates exhibited both vancomycin and linezolid resistance.
- A specific G-to-T single nucleotide polymorphism at bp 2576 in 23S rRNA genes was identified.
- This mutation was present in two of six alleles in both resistant isolates.
Findings:
- Pyrosequencing accurately quantified the G-to-T mutation proportion, serving as a marker for linezolid resistance.
- No other mutations in the 23S rRNA genes were detected in the resistant isolates.
- Dynamic reversion of resistant alleles to wild-type was observed in serial isolates, demonstrating the plasticity of resistance.
Implications:
- Pyrosequencing is a rapid and reliable method for detecting and monitoring linezolid resistance in Enterococcus faecium.
- The observed reversion of resistance suggests potential therapeutic strategies targeting resistance mechanisms.
- This research aids in managing infections caused by multidrug-resistant Enterococcus faecium.
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