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Comparative efficacy of pefloxacin and six other antimicrobial agents on Staphylococcus aureus experimental abscesses
Abstract:
Pefloxacin (Pef) is a new quinolone which has been shown to have good in-vitro activity against Staphylococcus aureus, and to reach high tissue concentrations. Its efficacy was compared to that of 2 quinolone derivatives, norfloxacin (Nor) and ciprofloxacin (Cip) and to that of methicillin (Meth), cephalothin (Cep), pristinamycin (Pri) and vancomycin (Van), in an experimental model of S. aureus abscesses. Mice challenged with an intramuscular thigh injection of a calibrated inoculum developed local abscesses. Three S. aureus strains (with different antibiotic resistance profiles (Pase-, Pase+, MethR)) were used. In this model, the antibiotics showing the best ED50 following oral administration, against all three strains were Pef greater than Cip greater than Pri greater than Nor, by subcutaneous administration for the Pase- strain Pef = Cip greater than Cep greater than Van; for the Pase+ strain Pef = Cip greater than Van greater than Meth and for the Pase+ MethR strain: Pef = Cip greater than Van greater than Cep. These data indicate that pefloxacin and ciprofloxacin are highly active in vivo against various strains of S. aureus, and appear to be more potent than norfloxacin, vancomycin, cephalothin and methicillin.
Insights
Pefloxacin and ciprofloxacin demonstrate potent in vivo activity against Staphylococcus aureus abscesses, outperforming other antibiotics. This study highlights their efficacy in an experimental mouse model with various bacterial resistance profiles.
Area of Science:
- Microbiology
- Pharmacology
- Infectious Diseases
Background:
- Staphylococcus aureus is a common pathogen causing abscesses.
- Pefloxacin exhibits promising in vitro activity and tissue penetration.
- Comparison with existing antibiotics is crucial for clinical application.
Purpose of the Study:
- To evaluate the in vivo efficacy of pefloxacin (Pef) against Staphylococcus aureus abscesses.
- To compare pefloxacin's efficacy with norfloxacin (Nor), ciprofloxacin (Cip), methicillin (Meth), cephalothin (Cep), pristinamycin (Pri), and vancomycin (Van).
- To assess antibiotic performance across different S. aureus strains with varying resistance patterns.
Main Methods:
- An experimental mouse model of S. aureus thigh abscesses was utilized.
- Three S. aureus strains with distinct resistance profiles (Pase-, Pase+, MethR) were employed.
- Antibiotic efficacy was determined by calculating the ED50 (effective dose for 50% inhibition) via oral and subcutaneous administration.
Main Results:
- Pefloxacin and ciprofloxacin showed superior efficacy (lower ED50) compared to other tested antibiotics across all S. aureus strains and administration routes.
- Oral administration results: Pefloxacin > Ciprofloxacin > Pristinamycin > Norfloxacin.
- Subcutaneous administration results varied slightly by strain but consistently showed Pefloxacin and Ciprofloxacin as most potent.
Conclusions:
- Pefloxacin and ciprofloxacin exhibit significant in vivo potency against diverse Staphylococcus aureus strains.
- These quinolone derivatives appear more effective than vancomycin, cephalothin, and methicillin in this abscess model.
- The findings support the potential clinical utility of pefloxacin and ciprofloxacin for S. aureus infections.