In vitro and in vivo activity of iclaprim, a diaminopyrimidine compound and potential therapeutic alternative against Pneumocystis pneumonia

Antistaphylococcal discovery pipeline; where are we now?

The serious spread of antibiotic-resistant Staphylococcal aureus strains is alarming. This is reflected by the measures governments and health-related bodies are offering to ease antibiotic drug development. Finding new active agents, preferably with novel mechanism of action, or even finding new targets for drug development are essential. In this review, we summarize the current status of novel antistaphylococcal agents undergoing clinical trials. We mainly discuss antistaphylococcal small molecules and peptides in the text with a special focus on their chemistry, while antistaphylococcal immunotherapy (antibodies) are mentioned in a summative table. This review shall serve as a summary that influences future synthetic efforts in the antistaphyloccocals development field.

The activity of the diaminopyrimidine dihydrofolate reducatase inhibitor, iclaprim, against Toxoplasma gondii in an in vitro model: a pilot study

The objective of this pilot study was to examine the activity of iclaprim, a diaminopyrimidine dihydrofolate reducatase inhibitor, in an in vitro infection model of infection with Toxoplasma gondii. Toxoplasma growth was assessed by enzyme linked immunoassay (ELISA) performed directly on the fixed cultures using a peroxidase labeled monoclonal antibody directed against the SAG-l surface protein of T. gondii. For each well, the results were expressed as optical density (OD) values. Iclaprim inhibited T. gondii growth at concentrations between 0.1 and 10 mg/L; the IC₅₀ was estimated at 0.26 mg/L (95% confidence interval 0.22-0.33). Iclaprim was about 10 times more active than trimethoprim, which had an IC₅₀ of 2.3 mg/L. Iclaprim demonstrated synergistic effects at concentrations of 0.02, 0.05 and 0.1 mg/L when combined with subinhibitory concentrations of sulfamethoxazole (0.1 or 0.02 mg/L). These results show that iclaprim is a potent inhibitor of T. gondii growth in vitro. In addition, iclaprim exhibited synergy in vitro when tested in the presence of sulfamethoxazole. Iclaprim should be further investigated as an agent for the treatment or prophylaxis of toxoplasmosis.