Linezolid, levofloxacin, and vancomycin against vancomycin-tolerant and fluoroquinolone-resistant Streptococcus pneumoniae in an in vitro pharmacodynamic model
Abstract
STUDY OBJECTIVE: To compare the pharmacodynamic profiles of linezolid, levofloxacin, and vancomycin against clinical strains of Streptococcus pneumoniae, including vancomycin-tolerant and fluoroquinolone-resistant isolates. DESIGN: In vitro pharmacodynamic model. SETTING: Biosafety level 2, university research laboratory. BACTERIAL STRAINS: Ciprofloxacin-susceptible (79), ciprofloxacin-resistant (R921), and vancomycin-tolerant (P9802-020) clinical strains of S. pneumoniae. INTERVENTION: An in vitro pharmacodynamic model was used to simulate standard dosing regimens of linezolid, levofloxacin, and vancomycin against the isolates 79, R921, and P9802-020. MEASUREMENTS AND MAIN RESULTS: Bacterial density was profiled over 48 hours. Minimum inhibitory concentrations (MICs) for linezolid, levofloxacin, and vancomycin, respectively were 1, 1, 0.5 microg/ml for isolate 79; 1, 4, 0.5 microg/ml for R921; and 0.5, 0.5, 0.5 microg/ml for P9802-020. Vancomycin minimum bactericidal concentration (MBC) values varied across large ranges for the tested strains. Linezolid achieved 99.9% kill against 79 and R921 by 24 and 28 hours, respectively. Levofloxacin achieved 99.9% kill against 79 and P9802-020 by 28 and 4 hours, respectively. Vancomycin achieved 99.9% kill against 79 and R921 by 8 and 24 hours, respectively. Levofloxacin did not demonstrate activity against R921 at the 48-hour end point. Minimal kill (< 2 log) at 48 hours was noted for vancomycin and linezolid against P9802-020.…
Read the paper
Related studies
- Severe clinical outcomes of COVID-19 associated with proton pump inhibitors: a nationwide cohort study with propensity score matching
- Levofloxacin-Induced Tendon Rupture: A Case Report and Review of the Literature
- 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)
- Neuroprotective Effects of Epicatechin against Oxidative Stress-Induced Cognitive Impairment: A Systematic Review and Meta-Analysis
- Quality evaluation and in vitro interaction studies between levofloxacin 250mg and diclofenac sodium 50mg tablets
- Molecular Epidemiology of mcr-1 -Positive Polymyxin B-Resistant Escherichia coli Producing Extended-Spectrum β-Lactamase (ESBL) in a Tertiary Hospital in Shandong, China
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.