Skip Navigation



JAC Advance Access published online on May 20, 2009
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkp184
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
64/2/310    most recent
dkp184v1
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 Krishnan, M. Y.
Right arrow Articles by Collins, M. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Krishnan, M. Y.
Right arrow Articles by Collins, M. T.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2009. 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

Original research

Comparison of three methods for susceptibility testing of Mycobacterium avium subsp. paratuberculosis to 11 antimicrobial drugs

Manju Y. Krishnan, Elizabeth J. B. Manning and Michael T. Collins*

Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin–Madison, 2015 Linden Drive, Madison, WI 53706-110, USA

Received 28 January 2009; returned 3 March 2009; revised 24 March 2009; accepted 27 April 2009

* Corresponding author. Tel: +1-608-262-8457; Fax: +1-608-265-6463; E-mail: mcollin5{at}wisc.edu

Objectives: To evaluate the BACTECTM MGITTM 960/MGIT Para TB (MGIT) system for drug susceptibility testing of Mycobacterium avium subsp. paratuberculosis (MAP), a pathogen implicated in some forms of Crohn's disease.

Methods: MICs of 11 drugs for 10 MAP strains were determined using the MGIT system, the BACTECTM460TB system (BACTEC) and conventional agar dilution methods.

Results: MICs determined by MGIT methods showed 80%–100% agreement (±1 log2 dilution) with those determined by the BACTEC and agar dilution methods for ciprofloxacin, levofloxacin, azithromycin and clofazimine. The MGIT and BACTEC methods showed 70%, 80% and 90% agreement (±1 log2 dilution) for MICs of ethambutol, rifabutin and rifampicin; agreement for all drugs increased to 100% at 2 log2 dilution differences. For clarithromycin, the MGIT method had greater agreement with the agar dilution method (70% at the same dilution) than the BACTEC method (60% at ±1 log2 dilution); agreement increased to 100% at ±2 log2 dilutions in both cases. The MGIT and agar dilution methods agreed 60% and 100% for amikacin MICs at ±1 log2 dilution and ±2 log2 dilutions, respectively. By all methods MICs were higher than achievable serum concentrations for isoniazid and dapsone. There was 100% agreement between all three methods for azithromycin, clarithromycin and ciprofloxacin, and 80% agreement for rifampicin using published MIC thresholds available for M. avium complex strains.

Conclusions: This study shows that the MGIT system can be used for rapid and reliable drug susceptibility testing of MAP.

Key Words: agar dilution , BACTEC , MGIT , MIC


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J Antimicrob ChemotherHome page
M. Y. Krishnan, E. J. B. Manning, and M. T. Collins
Effects of interactions of antibacterial drugs with each other and with 6-mercaptopurine on in vitro growth of Mycobacterium avium subspecies paratuberculosis
J. Antimicrob. Chemother., November 1, 2009; 64(5): 1018 - 1023.
[Abstract] [Full Text] [PDF]


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.