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Description of compensatory gyrA mutations restoring fluoroquinolone susceptibility in Mycobacterium tuberculosis
- Source :
- Journal of Antimicrobial Chemotherapy, Journal of Antimicrobial Chemotherapy, 2016, 71 (9), pp.2428-2431. ⟨10.1093/jac/dkw169⟩, Journal of Antimicrobial Chemotherapy, Oxford University Press (OUP), 2016, 71 (9), pp.2428-2431. ⟨10.1093/jac/dkw169⟩
- Publication Year :
- 2016
- Publisher :
- HAL CCSD, 2016.
-
Abstract
- International audience; OBJECTIVES:Resistance to fluoroquinolones (FQs) in Mycobacterium tuberculosis (Mtb) is mainly due to mutations in DNA gyrase (GyrA2B2), with the most common substitutions located at positions 90 and 94 in GyrA. Two clinical MDR Mtb (MDR-TB) strains harbouring an A90E or D94N substitution in GyrA were found to be surprisingly susceptible to FQs (ofloxacin MIC ≤2 mg/L). We studied the impact of the additional GyrA substitutions found in these strains (T80A and T80A + A90G, respectively) on FQ susceptibility.METHODS:Mutants of interest were generated by site-specific mutagenesis of GyrA alleles. WT and mutant TB DNA gyrase subunits were overexpressed in Escherichia coli and purified, and the in vitro susceptibility to FQs of their DNA supercoiling reaction was studied.RESULTS:IC50s of mutant gyrase complexes bearing GyrA D94N and A90E were 3- to 36-fold higher than WT IC50s, whereas IC50s of gyrase bearing T80A + A90G + D94N and T80A + A90E were close to the WT IC50s.CONCLUSIONS:We demonstrated that substitutions T80A and A90G restore FQ susceptibility when associated with a substitution implicated in high-level FQ resistance. Line probe assay misclassification of MDR-TB strains as pre-XDR or XDR can be corrected by sequence analysis of gyrA.
- Subjects :
- 0301 basic medicine
MESH: Mycobacterium tuberculosis
DNA Mutational Analysis
Mutant
Antitubercular Agents
medicine.disease_cause
DNA gyrase
MESH: Recombinant Proteins
Suppression, Genetic
[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases
Pharmacology (medical)
MESH: DNA Mutational Analysis
MESH: Suppression, Genetic
MESH: Inhibitory Concentration 50
Mutation
MESH: Microbial Sensitivity Tests
biology
Chemistry
MESH: Escherichia coli
Recombinant Proteins
3. Good health
MESH: Mutagenesis, Site-Directed
Infectious Diseases
[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology
DNA Gyrase
DNA supercoil
Fluoroquinolones
medicine.drug
MESH: DNA Gyrase
Microbiology (medical)
030106 microbiology
Mutation, Missense
Microbial Sensitivity Tests
Microbiology
Mycobacterium tuberculosis
Inhibitory Concentration 50
03 medical and health sciences
Drug Resistance, Bacterial
MESH: Drug Resistance, Bacterial
Escherichia coli
medicine
Humans
Pharmacology
MESH: Mutation, Missense
MESH: Humans
Mutagenesis
MESH: Fluoroquinolones
biology.organism_classification
MESH: Antitubercular Agents
Mutagenesis, Site-Directed
[SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology
Ofloxacin
Subjects
Details
- Language :
- English
- ISSN :
- 03057453 and 14602091
- Database :
- OpenAIRE
- Journal :
- Journal of Antimicrobial Chemotherapy, Journal of Antimicrobial Chemotherapy, 2016, 71 (9), pp.2428-2431. ⟨10.1093/jac/dkw169⟩, Journal of Antimicrobial Chemotherapy, Oxford University Press (OUP), 2016, 71 (9), pp.2428-2431. ⟨10.1093/jac/dkw169⟩
- Accession number :
- edsair.doi.dedup.....e5db11d2e1dccf5abd7c85ff0b05554f