1. Efficacy of Delafloxacin against the Biothreat Pathogen Burkholderia pseudomallei
- Author
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Stephanie A. Halasohoris, Sandra P. McCurdy, Erin M. Duffy, Mark Hickman, and Steven D. Zumbrun
- Subjects
Burkholderia pseudomallei ,Melioidosis ,Burkholderia ,Ceftazidime ,Clinical Therapeutics ,fluoroquinolone ,biothreat ,Microbiology ,Mice ,chemistry.chemical_compound ,delafloxacin ,In vivo ,Animals ,Medicine ,Pharmacology (medical) ,Pharmacology ,biology ,business.industry ,Broth microdilution ,bacterial infections and mycoses ,biology.organism_classification ,medicine.disease ,Anti-Bacterial Agents ,Infectious Diseases ,chemistry ,Tolerability ,Delafloxacin ,business ,Fluoroquinolones ,medicine.drug - Abstract
The in vitro activity and in vivo efficacy of delafloxacin were evaluated against the causative pathogen of melioidosis, Burkholderia pseudomallei. Delafloxacin MICs were determined by broth microdilution according to CLSI guidelines for 30 isolates of B. pseudomallei. The in vivo efficacy of delafloxacin was studied at a range of doses in a postexposure prophylaxis (PEP) murine model of melioidosis. Delafloxacin was active in vitro against B. pseudomallei (MIC90, 1 μg/ml). When the mice were dosed with 50 mg/kg body weight and 80 mg/kg body weight delafloxacin at both 16 and 24 h, greater survival was observed (90% to 100% survival) than with the 30-mg/kg-dosed mice (70% survival). All delafloxacin-treated cohorts contained no detectable B. pseudomallei in the spleens at the end of the study. This contrasts with ceftazidime 16- and 24-h administration, which had 40% and 20% survival, respectively. Complete clearance of infection was observed for most but not all surviving cohorts administered ceftazidime. In the mouse model of infection, survival curves for delafloxacin- and ceftazidime-treated animals at treatment start times of 16 and 24 h were statistically significant (P values of
- Published
- 2021
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