JCM Figure table search 04
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Frebourg, N. B.
Right arrow Articles by Lemeland, J.-F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Frebourg, N. B.
Right arrow Articles by Lemeland, J.-F.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, January 1998, p. 52-57, Vol. 36, No. 1
0095-1137/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Comparison of ATB Staph, Rapid ATB Staph, Vitek, and E-Test Methods for Detection of Oxacillin Heteroresistance in Staphylococci Possessing mecA

Noëlle Barbier Frebourg,* Delphine Nouet, Ludovic Lemée, Emmanuelle Martin, and Jean-François Lemeland

Laboratoire de Bactériologie, CHU de Rouen, Hôpital Charles Nicolle, 76031 Rouen Cedex, France

Received 23 June 1997/Returned for modification 22 August 1997/Accepted 15 October 1997

The performance characteristics of the E-test (AB Biodisk, Solna, Sweden), the ATB Staph, the Rapid ATB Staph, and the Vitek GPS-503 card (bioMérieux, La Balme Les Grottes, France) methods for the detection of oxacillin resistance in a collection of staphylococci with a high proportion of troublesome strains were evaluated. Sixty-four Staphylococcus aureus strains and 76 coagulase-negative staphylococcal strains were tested. All strains were mecA positive and were characterized by the oxacillin agar screen plate test; 75 (53.6%) were found to be heterogeneous by a large-inoculum oxacillin disk diffusion assay, and oxacillin MICs for 89 (63.6%) were <= 32 µg/ml. Three (4.7%) S. aureus strains and 25 (32.9%) coagulase-negative strains were classified as susceptible by the E-test, as defined by the National Committee for Clinical Laboratory Standards (NCCLS) oxacillin breakpoint (MIC <=  2 µg/ml). The ATB Staph method failed to detect oxacillin resistance in 7 (11%) S. aureus isolates and 32 (42.1%) coagulase-negative isolates. The MICs for all but six of these discrepant isolates were <= 16 µg/ml. The Rapid ATB Staph method was tested against S. aureus strains only and yielded 15 (23.4%) false-susceptible results for strains for which the MICs were <= 32 µg/ml. The Vitek system was the best-performing system, since it failed to detect oxacillin resistance in only 3 (4.7%) S. aureus strains and 15 (19.7%) coagulase-negative strains, the MICs for all of which were <= 2 µg/ml. These data indicate that (i) the performance of the two ATB Staph systems can be limited when the prevalence of borderline-heteroresistant staphylococci is high and (ii) the unreliability of the E-test and the Vitek methods for detecting resistant coagulase-negative strains might be reduced by the potential revision of the oxacillin breakpoint currently recommended by the NCCLS.

* Corresponding author. Mailing address: C.H.U. de Rouen, Hôpital Charles Nicolle, Laboratoire de Bactériologie, 1, rue de Germont, 76031 Rouen Cedex, France. Phone: 33 2 32 88 80 52. Fax: 33 2 32 88 80 24. E-mail: bacteriologie{at}chu-rouen.fr.

Journal of Clinical Microbiology, January 1998, p. 52-57, Vol. 36, No. 1
0095-1137/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Antimicrob. Agents Chemother. Clin. Microbiol. Rev.
Clin. Vaccine Immunol. ALL ASM JOURNALS

Copyright © 1998 by the American Society for Microbiology. All rights reserved.