Related Experiment Videos
[Sensitivity of penicillin-resistance pneumococci]
1Pharma-Forschung/Infectious Diseases, F. Hoffmann-La Roche AG, Basel.
Abstract:
Fifty-three clinical Streptococcus pneumoniae isolates from Hungary and Spain which were either moderately susceptible to penicillin G (MIC 0.25-1 mg/l) or highly resistant (MIC > or = 2 mg/l) were studied for their antibacterial susceptibility to the following 14 agents: penicillin G, amoxicillin, mezlocillin, cefotaxime, ceftriaxone, amikacin, cotrimoxazole, erythromycin, rifampicin, vancomycin, fosfomycin, doxycycline, ciprofloxacin, and the dual-action compound Ro 23-9424. Rifampicin was the most active compound (MIC90 < or = 0.015 mg/l) followed by imipenem (MIC90 0.25 mg/l), vancomycin (MIC90 1 mg/l), cefotaxime and ceftriaxone (MIC90 1 mg/l), the dual-action compound Ro 23-9424 and amoxicillin (MIC90 2 mg/l). Most of the isolates were less sensitive to ciprofloxacin (MIC90 4 mg/l), doxycycline and erythromycin (MIC90 16 mg/l) and resistant to cotrimoxazole (MIC90 640 mg/l). Furthermore, synergism between penicillin G or ceftriaxone on the one hand, amikacin or rifampicin on the other hand was studied in all 53 isolates. A combination of a beta-lactam with amikacin resulted mostly in an additive effect, as was the case for the rifampicin combinations. The selection of rifampicin-resistant clones can be repressed by the addition of a beta-lactam thus suggesting such a combination of rifampicin with a beta-lactam as a possible therapeutic approach.
Insights
This study evaluated 53 Streptococcus pneumoniae isolates against 14 antibiotics. Rifampicin showed high activity, and combining it with beta-lactams may prevent resistance.
Area of Science:
- Microbiology
- Pharmacology
- Infectious Diseases
Context:
- Antibiotic resistance in Streptococcus pneumoniae is a growing global health concern.
- Penicillin-resistant strains of S. pneumoniae pose significant treatment challenges.
- Understanding susceptibility patterns is crucial for effective antimicrobial therapy.
Purpose:
- To assess the in vitro activity of 14 antimicrobial agents against clinical isolates of Streptococcus pneumoniae.
- To investigate potential synergistic effects between beta-lactams and other antibiotics.
- To explore therapeutic strategies to overcome antibiotic resistance in S. pneumoniae.
Summary:
- Fifty-three clinical isolates of Streptococcus pneumoniae with varying penicillin G susceptibility were tested against 14 agents.
- Rifampicin demonstrated the highest in vitro activity, followed by imipenem, vancomycin, cefotaxime, ceftriaxone, Ro 23-9424, and amoxicillin.
- Combinations of beta-lactams with amikacin or rifampicin showed additive effects, with beta-lactam addition potentially inhibiting rifampicin resistance.
Impact:
- Identifies rifampicin as a potent agent against S. pneumoniae isolates.
- Suggests a combination therapy of rifampicin with a beta-lactam as a potential strategy to combat resistance.
- Provides valuable data for guiding antimicrobial selection in treating S. pneumoniae infections.