Wild-Type and Non-Wild-Type Mycobacterium tuberculosis MIC Distributions for the Novel Fluoroquinolone Antofloxacin Compared with Those for Ofloxacin, Levofloxacin, and Moxifloxacin

Mycobacterium tuberculosis wild-type and non-wild-type MIC distributions for the novel fluoroquinolone antofloxacin compared with ofloxacin, levofloxacin, and moxifloxacin

Wild-type MIC distributions of four fluoroquinolones active against Mycobacterium tuberculosis in relation to current critical concentrations and available pharmacokinetic and pharmacodynamic data.

OBJECTIVES To describe wild-type distributions of the MIC of fluoroquinolones for Mycobacterium tuberculosis in relation to current critical concentrations used for drug susceptibility testing and pharmacokinetic/pharmacodynamic (PK/PD) data. METHODS A 96-stick replicator on Middlebrook 7H10 medium was used to define the MICs of ciprofloxacin, ofloxacin, moxifloxacin and levofloxacin for 90 c...

Impact of fluoroquinolone resistance on bactericidal and sterilizing activity of a moxifloxacin-containing regimen in murine tuberculosis.

It has been shown previously that fluoroquinolone resistance (defined by resistance to at least 2 mg/liter ofloxacin) has a different impact on moxifloxacin monotherapy depending on the mutation in the sole fluoroquinolone target in Mycobacterium tuberculosis, i.e., DNA gyrase. Since tuberculosis treatment relies on multidrug therapy, we wished to determine the impact of fluoroquinolone resista...

DNA gyrase inhibition assays are necessary to demonstrate fluoroquinolone resistance secondary to gyrB mutations in Mycobacterium tuberculosis.

The main mechanism of fluoroquinolone (FQ) resistance in Mycobacterium tuberculosis is mutation in DNA gyrase (GyrA(2)GyrB(2)), especially in gyrA. However, the discovery of unknown mutations in gyrB whose implication in FQ resistance is unclear has become more frequent. We investigated the impact on FQ susceptibility of eight gyrB mutations in M. tuberculosis clinical strains, three of which w...

Fluoroquinolone resistance in Mycobacterium tuberculosis: an assessment of MGIT 960, MODS and nitrate reductase assay and fluoroquinolone cross-resistance.

OBJECTIVES The aim of this study was to assess the sensitivity, specificity and time to results of mycobacterial growth indicator tube (MGIT) 960, microscopic observation drug susceptibility (MODS) assay and nitrate reductase assay (NRA) compared with the gold standard agar proportion method (PM), and to determine whether there is cross-resistance between older-generation fluoroquinolones and m...