Moxifloxacin's Limited Efficacy in the Hollow-Fiber Model of Mycobacterium abscessus Disease
Abstract
Current regimens used to treat pulmonary Mycobacterium abscessus disease have limited efficacy. There is an urgent need for new drugs and optimized combinations and doses. We performed hollow-fiber-system studies in which M. abscessus was exposed to moxifloxacin lung concentration-time profiles similar to human doses of between 0 and 800 mg/day. The minimum bactericidal concentration and MIC were 8 and 2 mg/liter, respectively, in our M. abscessus strain, suggesting bactericidal activity. Measurement of the moxifloxacin concentrations in each hollow-fiber system revealed an elimination rate constant (kel) of 0.11 ± 0.05 h(-1) (mean ± standard deviation) (half-life of 9.8 h). Inhibitory sigmoid maximal effect (Emax) modeling revealed that the highest Emax was 3.15 ± 1.84 log10 CFU/ml on day 3, and the exposure mediating 50% of Emax (EC50) was a 0- to 24-h area under the concentration time curve (AUC0-24)-to-MIC ratio of 41.99 ± 31.78 (r(2) = 0.99). The EC80 was an AUC0-24/MIC ratio of 102.11. However, no moxifloxacin concentration killed the bacteria to burdens below the starting inoculum. There was regrowth beyond day 3 in all doses, with replacement by a resistant subpopulation that had an MIC of >32 mg/liter by the end of the experiment. A quadratic function best described the relationship between the AUC0-24/MIC ratio and the moxifloxacin-resistant subpopulation. Monte Carlo simulations of 10,000 patients revealed that the 400- to 800-mg/day doses would achieve or exceed…
Read the paper
Related studies
- Structural and topological analysis of thiosemicarbazone-based metal complexes: computational and experimental study of bacterial biofilm inhibition and antioxidant activity
- Toward better cures for Mycobacterium abscessus lung disease
- Challenges for global antibiotic regimen planning and establishing antimicrobial resistance targets: implications for the WHO Essential Medicines List and AWaRe antibiotic book dosing
- Design, Synthesis and In vitro Antitubercular Effect of New Chalcone Derivatives Coupled with 1,2,3‐Triazoles: A Computational Docking Techniques
- Upregulation of pmrA, pmrB, pmrC, phoQ, phoP, and arnT genes contributing to resistance to colistin in superbug Klebsiella pneumoniae isolates from human clinical samples in Tehran, Iran
- Whole-genome sequencing of clinical isolates of Citrobacter Europaeus in China carrying blaOXA−48 and blaNDM−1
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.