Molecular characterisation of linezolid resistance in two vancomycin-resistant (VanB) Enterococcus faecium isolates using Pyrosequencing

• Published in: European journal of clinical microbiology & infectious diseases Vol. 27; no. 9; pp. 873 - 878
• Main Authors: Saager, B., Rohde, H., Timmerbeil, B. S., Franke, G., Pothmann, W., Dahlke, J., Scherpe, S., Sobottka, I., Heisig, P., Horstkotte, M. A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2008; Springer; Springer Nature B.V
• Subjects: Acetamides - pharmacology; Adult; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotic resistance; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Concise Article; Drug Resistance, Multiple, Bacterial - genetics; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecium - drug effects; Enterococcus faecium - genetics; Enterococcus faecium - isolation & purification; Female; Genes, Bacterial; Genes, rRNA; Gram-Positive Bacterial Infections - microbiology; Humans; Infectious diseases; Internal Medicine; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - complications; Linezolid; Medical Microbiology; Medical sciences; Microbial Sensitivity Tests; Monitoring methods; Mucositis - complications; Mutation; Oxazolidinones - pharmacology; Pancreatitis, Acute Necrotizing - complications; Pharmacology. Drug treatments; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Sequence Analysis, DNA; Vancomycin - pharmacology; Vancomycin Resistance - genetics; Linezolid; Linezolid Resistance; Teicoplanin; Daptomycin; Glycopeptide Resistance; Microbiology; Infection; Resistance; Streptococcaceae; Enterococcus faecium; Antibiotic; Oxazolidinone derivative; Bacteria; Micrococcales; Protein synthesis inhibitor; Antibacterial agent; Oxazole derivatives
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-008-0514-6

In this paper, we describe the phenotypic and molecular characteristics of two clinically relevant, vancomycin-resistant (VanB), linezolid-resistant Enterococcus faecium isolates. Pyrosequencing™ showed the G to T single nucleotide polymorphism at bp 2576 in the genes coding for 23S rRNA and was used to quantify the proportion of G to T mutations among six different 23S rRNA genes in E. faecium as a marker for the molecular level of resistance to linezolid. In both isolates, the G to T mutation was found in two of six alleles, and no further mutations in the genes coding for 23S rRNA were found. The dynamic process of linezolid resistance could be demonstrated by the complete reversion of resistant alleles back to only wild type alleles in consecutive isolates of one isolate. Pyrosequencing™ being used to detect and quantify resistance to linezolid has been proven as a fast and reliable molecular screening method for monitoring linezolid resistance.