Background: 14 linezolid-resistant enterococci (6 Enterococcus faecium and 8 Enterococcus faecalis) collected during 2009 from patients hospitalized in intensive care units of different Greek hospitals were investigated. Methods: The mechanism of resistance to linezolid was determined by sequencing analysis of the domain V of 23S rDNA, while the clonal relatedness was defined by pulsed-field gel electrophoresis and multilocus sequence typing. Results: All linezolid-resistant enterococci carried the G2576T mutation. E. faecium belonged to the international epidemic clones ST16, ST17, ST203 and ST65, while all E. faecalis strains belonged to the ST28 clone. Conclusions: The spread of common linezolid-resistant enterococcal clones in intensive care units located in different areas of Greece emphasizes the importance of application of infection control measures to prevent the spread of such strains.

Livermore DM: Linezolid in vitro: mechanism and antibacterial spectrum. J Antimicrob Chemother 2003;51(suppl 2):ii9–ii16.
Meka VG, Gold HS: Antimicrobial resistance to linezolid. Clin Infect Dis 2004;39:1010–1015.
Prystowsky J, Siddiqui F, Chosay J, Shinabarger DL, MillichapJ, Peterson LR, et al: Resistance to linezolid: characterization of mutations in rRNA and comparison of their occurrences in vancomycin-resistant enterococci. Antimicrob Agents Chemother 2001;45:2154–2156.
Rahim S, Pillai SK, Gold HS, Venkataraman L, Inglima K, Press RA: Linezolid-resistant, vancomycin-resistant Enterococcus faecium infection in patients without prior exposure to linezolid. Clin Infect Dis 2003;36:146–148.
Pratti A, Karanika M, Maniatis AN, Petinaki E, Spiliopoulou I, Kolonitsiou F, Tatsiopoulos A, Alexiou-Daniel S, Bakola D, Koutsia-Carousou C, Malamou-Lada H, Siafakas N, Zerva L: Activity of linezolid against Gram-positive cocci: a multicenter study in Greek hospitals. Int J Antimicrob Agents 2007;29:604–605.
Clinical and Laboratory Standards Institute: Performance Standards for Antimicrobial Susceptibility Testing; Nineteenth Informational Supplement, ed 10. Approved standard M100-S19. Wayne, CLSI, 2009.
Jackson CR, Fedorka-Cray PJ, Barrett JB: Use of a genus- and species-specific multiplex PCR for identification of enterococci.J Clin Microbiol 2004;42:3558–3565.
Bourgeois-Nicolaos N, Massias L, Couson B, Butel MJ, Andremont A, Doucet-Populaire F: Dose dependence of emergence of resistance to linezolid in Enterococcus faecalis in vivo. J Infect Dis 2007;195:1480–1488.
Pillai SK, Sakoulas G, Wennersten C, Eliopoulos GM, Moellering RC, Ferraro MJ, et al: Linezolid resistance in Staphylococcus aureus: characterization and stability of resistant phenotype. J Infect Dis 2002;186:1603–1607.
Morrison D, Woodford N, Barrett SP, Sisson P, Cookson BD: DNA banding pattern polymorphism in vancomycin-resistant Enterococcus faecium and criteria for defining strains. J Clin Microbiol 1999;37:1084–1091.
Tenover FC, Arbeit RD, Goering RV, Mickelsen PA, Murray BE, Persing DH, et al: Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol 1995;33:2233–2239.
Homan WL, Tribe D, Poznanski S, Li M, Hogg G, Spalburg E, et al: Multilocus sequence typing scheme for Enterococcus faecium. J Clin Microbiol2002;40:1963–1971.
Nallapareddy SR, Duh RW, Singh KV, Murray BE: Molecular typing of selected Enterococcusfaecalis isolates: pilot study using multilocus sequence typing and pulsed-field gel electrophoresis. J Clin Microbiol 2002;40:868–876.
Dobbs TE, Patel M, Waites KB, Moser SA, Stamm AM, Hoesley CJ: Nosocomial spread of Enterococcus faecium resistant to vancomycin and linezolid in a tertiary care medical center. J Clin Microbiol 2006;44:3368–3370.
Marshall SH, Donskey CJ, Hutton-Thomas R, Salata RA, Rice LB: Gene dosage and linezolid resistance in Enterococcus faecium and Enterococcus faecalis. Antimicrob Agents Chemother 2002;46:3334–3336.
Damani A, Klapsa D, Panopoulou M, Spiliopoulou I, Pantelidi K, Malli E, et al: A newly described vancomycin-resistant ST412 Enterococcus faecium predominant in Greek hospitals. Eur J Clin Microbiol Infect Dis 2010;29:329–331.
Souli M, Sakka V, Galani I, et al: Colonisation with vancomycin- and linezolid-resistant Enterococcus faecium in a university hospital: molecular epidemiology and risk factor analysis. Int J Antimicrob Agents 2009;33:137–142.
Malli E, Spiliopoulou I, Kolonitsiou F, et al: In vitro activity of daptomycin against Gram-positive cocci: the first multicentre study in Greece. Int J Antimicrob Agents 2008;32:525–528.
Draghi D, Tench S, Dowzicky M, Sahm D: Baseline in vitro activity of tigecycline among key bacterial pathogens exhibiting multidrug resistance. Chemotherapy 2008; 54:91–100.
Canigia L, Kaufman S, Lanata L, et al: Multicenter study to assess the in vitro activity of tigecycline by disk diffusion test against clinical isolates from Argentina. Chemotherapy 2009;55:20–27.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.