Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Mycobacterium tuberculosis strains with highly discordant rifampin susceptibility test results
Author: Van Deun, A.
Barrera, L.
Bastian, I.
Fattorini, L.
Hoffmann, H.
Kam, K.
Rigouts, L.
Rusch-Gerdes, S.
Wright, A.
Citation: Journal of Clinical Microbiology, 2009; 47(11):3501-3506
Publisher: Amer Soc Microbiology
Issue Date: 2009
ISSN: 0095-1137
Statement of
A. Van Deun, L. Barrera, I. Bastian, L. Fattorini, H. Hoffmann, K. M. Kam, L. Rigouts, S. Rüsch-Gerdes and A. Wright
Abstract: The objectives of this study were to investigate the origin of highly discordant rifampin (rifampicin) (RMP) drug susceptibility test results obtained for Mycobacterium tuberculosis strains during proficiency testing. Nine Supra-National Tuberculosis Reference Laboratories tested the RMP susceptibilities of 19 selected M. tuberculosis strains, using standard culture-based methods. The strains were classified as definitely resistant (R) (n = 6) or susceptible (S) (n = 2) or probably resistant (PR) (n = 8) or susceptible (PS) (n = 3) based on rpoB mutations and treatment outcome. All methods yielded a susceptible result for the two S and three PS strains lacking an rpoB mutation and a resistant result for one R strain with a Ser531Leu mutation and one PR strain with a double mutation. Although the remaining 12 R and PR strains had rpoB mutations (four Asp516Tyr, three Leu511Pro, two Leu533Pro, one each His526Leu/Ser, and one Ile572Phe), they were all susceptible by the radiometric Bactec 460TB or Bactec 960 MGIT methods. In contrast, only one was susceptible by the proportion method on Löwenstein-Jensen medium and two on Middlebrook 7H10 agar. Low-level but probably clinically relevant RMP resistance linked to specific rpoB mutations is easily missed by standard growth-based methods, particularly the automated broth-based systems. Further studies are required to confirm these findings, to determine the frequency of these low-level-resistant isolates, and to identify technical improvements that may identify such strains.
Keywords: Humans
Mycobacterium tuberculosis
DNA-Directed RNA Polymerases
Antitubercular Agents
Microbial Sensitivity Tests
Mutation, Missense
Description: Copyright © 2009, American Society for Microbiology. All Rights Reserved.
DOI: 10.1128/JCM.01209-09
Published version:
Appears in Collections:Aurora harvest 5
Molecular and Biomedical Science publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.