In vitro bactericidal activity of iclaprim in human plasma

Area of Science:

• Pharmacology and Microbiology
• Antimicrobial Agents
• Bacterial Infections

Background:

• Staphylococcus aureus, including methicillin-resistant strains, poses a significant threat in healthcare settings.
• Novel antimicrobial agents are crucial to combat rising antibiotic resistance.
• Understanding drug behavior in biological fluids like plasma is essential for efficacy.

Purpose of the Study:

• To assess the impact of human plasma on the in vitro bactericidal activity of iclaprim.
• To determine the efficacy of iclaprim against methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA) in a plasma environment.

Main Methods:

• Determination of Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) of iclaprim.
• Evaluation of iclaprim's activity in the presence and absence of 50% human plasma.
• Quantification of bacterial (CFU) reduction over time to assess bactericidal kinetics.

Main Results:

• Iclaprim demonstrated potent activity with MICs and MBCs ranging from 0.06 to 0.125 microg/ml.
• Approximately 93% protein binding did not significantly alter iclaprim's MICs and MBCs in 50% human plasma.
• Iclaprim achieved a > or = 99.9% reduction in Colony Forming Units (CFU) within 5.0 to 7.6 hours, unaffected by plasma.

Conclusions:

• Human plasma does not impede the in vitro bactericidal activity of iclaprim against Staphylococcus aureus.
• Iclaprim exhibits robust antimicrobial properties, suggesting potential for treating S. aureus infections.
• The drug's efficacy is maintained despite significant protein binding and presence of plasma components.