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[The effect of pharmacodynamic parameters of pefloxacin on elastase and protease activity in Pseudomonas aeruginosa]
1Ustav preventívnej a klinickej medicíny, Bratislava.
Abstract:
The effect on Pseudomonas aeruginosa virulence factors (elastase and proteinase) after short-time treatment (30 min) with suprainhibitory (2x or 4x MIC) as well as with supra-subinhibitory concentrations (2x MIC + sub-MICs or 4x MIC + sub-MICs) of pefloxacin was studied. An effective decrease of elastase activity (to 42.6% of the control value) was observed only after higher suprainhibitory antibiotic concentration. More significant depression of the activities tested was found after the postantibiotic effect of subinhibitory concentrations. Elastase as well as proteinase activity were suppressed by supra-subinhibitory concentration of 4x MIC + 0.1x MIC to 13.1% or 37.9%, as compared to controls.
Insights
Peffloxacin significantly reduced Pseudomonas aeruginosa virulence factors like elastase and proteinase. Supra-subinhibitory concentrations, particularly after a postantibiotic effect, showed the most substantial suppression of these bacterial virulence factors.
Area of Science:
- Microbiology
- Pharmacology
- Infectious Diseases
Background:
- Pseudomonas aeruginosa is an opportunistic pathogen known for producing virulence factors.
- Elastase and proteinase are key enzymes contributing to P. aeruginosa pathogenesis.
- Antibiotic treatment can modulate bacterial virulence factor production.
Purpose of the Study:
- To investigate the impact of pefloxacin treatment on Pseudomonas aeruginosa elastase and proteinase activity.
- To evaluate the effects of both suprainhibitory and supra-subinhibitory concentrations of pefloxacin.
- To assess the role of postantibiotic effect in modulating virulence factor expression.
Main Methods:
- Treatment of Pseudomonas aeruginosa with varying concentrations of pefloxacin (2x MIC, 4x MIC, 2x MIC + sub-MICs, 4x MIC + sub-MICs) for 30 minutes.
- Measurement of elastase and proteinase activity in bacterial cultures post-treatment.
- Analysis of virulence factor suppression under different antibiotic exposure conditions, including postantibiotic effect.
Main Results:
- Higher suprainhibitory concentrations of pefloxacin (4x MIC) led to a decrease in elastase activity (42.6% of control).
- Supra-subinhibitory concentrations (4x MIC + 0.1x MIC) combined with postantibiotic effect demonstrated more significant suppression of elastase (13.1%) and proteinase (37.9%).
- Sub-MIC concentrations following higher antibiotic exposure were particularly effective in reducing virulence factor production.
Conclusions:
- Peffloxacin, especially at supra-subinhibitory concentrations and during the postantibiotic effect, can effectively suppress key Pseudomonas aeruginosa virulence factors.
- Modulating antibiotic concentrations and considering the postantibiotic effect may offer novel strategies to control P. aeruginosa infections by targeting virulence.
- This study highlights the potential of sub-inhibitory antibiotic concentrations in combination therapy to attenuate bacterial pathogenicity.