Erm(41)-dependent inducible resistance to azithromycin and clarithromycin in clinical isolates of Mycobacterium abscessus.
- Maurer FP Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland Nationales Zentrum für Mykobakterien, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland.
- Castelberg C Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland.
- Quiblier C Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland.
- Böttger EC Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland Nationales Zentrum für Mykobakterien, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland.
- Somoskövi A Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland Nationales Zentrum für Mykobakterien, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland asomoskoevi@imm.uzh.ch.
- 2014-02-07
Published in:
- The Journal of antimicrobial chemotherapy. - 2014
drug susceptibility testing
inducible resistance
macrolides
rapidly growing mycobacteria
Anti-Bacterial Agents
Azithromycin
Bacterial Proteins
Clarithromycin
Culture Media
Drug Resistance, Bacterial
Genes, Bacterial
Humans
Macrolides
Microbial Sensitivity Tests
Mycobacterium
English
OBJECTIVES
The ribosomal methylase Erm(41) confers inducible resistance to macrolides in Mycobacterium abscessus. The aim of this work was to systematically study and compare drug susceptibility to clarithromycin and azithromycin in M. abscessus and Mycobacterium chelonae clinical isolates with a particular focus on inducible drug resistance.
METHODS
Clinical isolates of M. abscessus subsp. abscessus (n = 21), M. abscessus subsp. bolletii (n = 16), M. abscessus subsp. massiliense (n = 10) and M. chelonae (n = 22) were characterized regarding their erm(41) and rrl genotypes and subjected to drug susceptibility testing (DST) for clarithromycin and azithromycin. Microdilution DST was performed in cation-adjusted Mueller-Hinton broth (pH 7.4) with readings at days 3, 7 and 12 and with pre-incubation at subinhibitory macrolide concentrations for erm(41) induction. In addition, the influence of variations in pH and growth medium on DST results was examined.
RESULTS
MICs of azithromycin were consistently higher than those of clarithromycin. In strains with an inducible erm(41) gene, high median MICs of ≥256 mg/L on day 12 were observed for both clarithromycin and azithromycin. Inducible resistance was at least as pronounced for azithromycin as for clarithromycin.
CONCLUSIONS
Our findings do not support the suggestion of a preferential use of azithromycin over clarithromycin in order to limit inducible macrolide resistance. Both compounds provoked a comparable resistance phenotype in M. abscessus. Caution is needed when using either azithromycin or clarithromycin for treatment of M. abscessus infections.
The ribosomal methylase Erm(41) confers inducible resistance to macrolides in Mycobacterium abscessus. The aim of this work was to systematically study and compare drug susceptibility to clarithromycin and azithromycin in M. abscessus and Mycobacterium chelonae clinical isolates with a particular focus on inducible drug resistance.
METHODS
Clinical isolates of M. abscessus subsp. abscessus (n = 21), M. abscessus subsp. bolletii (n = 16), M. abscessus subsp. massiliense (n = 10) and M. chelonae (n = 22) were characterized regarding their erm(41) and rrl genotypes and subjected to drug susceptibility testing (DST) for clarithromycin and azithromycin. Microdilution DST was performed in cation-adjusted Mueller-Hinton broth (pH 7.4) with readings at days 3, 7 and 12 and with pre-incubation at subinhibitory macrolide concentrations for erm(41) induction. In addition, the influence of variations in pH and growth medium on DST results was examined.
RESULTS
MICs of azithromycin were consistently higher than those of clarithromycin. In strains with an inducible erm(41) gene, high median MICs of ≥256 mg/L on day 12 were observed for both clarithromycin and azithromycin. Inducible resistance was at least as pronounced for azithromycin as for clarithromycin.
CONCLUSIONS
Our findings do not support the suggestion of a preferential use of azithromycin over clarithromycin in order to limit inducible macrolide resistance. Both compounds provoked a comparable resistance phenotype in M. abscessus. Caution is needed when using either azithromycin or clarithromycin for treatment of M. abscessus infections.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1093/jac/dku007
- PMID 24500188
- Persistent URL
- https://folia.unifr.ch/global/documents/251692
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