In vitro characterization of delafloxacin activity against intracellular Legionella: Exploring new treatment options for Legionnaires' disease
Abstract
Objectives: Delafloxacin is a fourth-generation fluoroquinolone that is currently approved in Europe and the United States for bacterial infections of the skin and skin structures and for community-acquired pneumonia, including cases where it is caused by atypical pathogens. It has demonstrated superior efficacy against a broad spectrum of bacteria and fewer adverse effects compared with other quinolones, such as levofloxacin, a current first-line treatment against Legionnaires' disease. This study aimed to characterize for the first time the intracellular activity of delafloxacin compared with levofloxacin against various serogroups of Legionella pneumophila and species of Legionella in terms of culturability and viability.
Methods: The infectious capacity of 10 Legionella strains was evaluated individually to ensure a percentage of viable infected macrophage post-infection. Then, the extracellular concentration inhibiting intracellular multiplication (MIEC90) of the antibiotic was determined by gradient antibiotic incubations in the in vitro infection model through culturability assays. Finally, the viability of intracellular Legionella was studied by quantitative polymerase chain reaction after antibiotic treatment at MIEC90 value.
Results: Delafloxacin decreased the culturability of Legionella from five to 10 times more than levofloxacin. The MIEC90 obtained was 0.025 mg/l for levofloxacin and 0.005 mg/l for delafloxacin for all strains tested, except L. longbeachae; the…
Read the paper
Related studies
- Severe clinical outcomes of COVID-19 associated with proton pump inhibitors: a nationwide cohort study with propensity score matching
- Penicillins for Treatment of Pneumococcal Pneumonia: Does In Vitro Resistance Really Matter?
- Thiophenes—Naturally Occurring Plant Metabolites: Biological Activities and In Silico Evaluation of Their Potential as Cathepsin D Inhibitors
- Inhalable Mannosylated Rifampicin–Curcumin Co-Loaded Nanomicelles with Enhanced In Vitro Antimicrobial Efficacy for an Optimized Pulmonary Tuberculosis Therapy
- Development and validation of microbial bioassay for quantification of Levofloxacin in pharmaceutical preparations
- Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA)
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.