Skip Navigation



JAC Advance Access published online on May 30, 2006
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkl216
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
58/1/108    most recent
dkl216v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
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 Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Schafer, J. A.
Right arrow Articles by Rotschafer, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schafer, J. A.
Right arrow Articles by Rotschafer, J. C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org
Received September 7, 2005
Revised February 1, 2006
Accepted May 8, 2006

Original article

Consistent rates of kill of Staphylococcus aureus by gentamicin over a 6-fold clinical concentration range in an in vitro pharmacodynamic model (IVPDM)

Jeremy A. Schafer 1, Laurie B. Hovde 1, and John C. Rotschafer 1 *

1 Antibiotic Pharmacodynamic Research Institute, Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA

* To whom correspondence should be addressed.
John C. Rotschafer, E-mail: rotsc001{at}umn.edu


  Abstract

Objectives: To compare the effect of a 6-fold range in gentamicin concentration on the bacterial killing of Staphylococcus aureus.

Methods: Six 24 h duplicate experiments were performed using an in vitro pharmacodynamic model (IVPDM) which was inoculated with 106 cfu/mL S. aureus (ATCC 29213) and subjected to desired initial gentamicin concentrations of 0, 5, 10, 15 and 20 mg/L. A 2 h half-life was emulated for gentamicin. Samples were drawn at 0.5, 1, 1.5, 2, 3, 4, 6, 9 and 24 h to quantify cfu/mL and gentamicin concentration. These samples were subjected to serial saline dilution to prevent antibiotic carryover and to produce a countable number of colonies. Pre- and post-gentamicin MIC values were performed for S. aureus. Duplicate 24 h kill curves were generated for each experiment and assessed for statistical difference (two-way ANOVA) between the slopes of the kill curves and time to 3 log kill.

Results: Kill curve slopes were analysed out to the 2 h time point and no statistical difference was found between the different concentrations (P > 0.05). Time to 3 log kill was not significantly different between the concentrations. Post-exposure gentamicin MIC values were within one tube dilution of the pre-exposure MIC value (0.25 mg/L).

Conclusions: These data demonstrate that clinical gentamicin concentrations kill S. aureus with equivalent effectiveness and that the use of higher doses of aminoglycosides would probably not improve bacterial kill rates.

Keywords: single daily dose; adjunctive aminoglycosides; S. aureus; pharmacodynamics.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.