Fig. 2.

Characterization of platencin. (A) In vivo studies on platencin. Dosing at 150 μg/h showed a 3-log reduction of viable S. aureus cell from the infected kidney compared with the control (vehicle). Error bars indicate standard deviation observed with seven infected mice upon treatment with platencin (treatment group) and five without treatment (control group). S. aureus Smith strain 4 × 10³ cfu/ml in 5% hog gastric mucin, and 0.5 ml was used to infect i.p., and 30 min after infection the drug was delivered by continuous infusion. After the 24-h period, the mice were killed immediately and the kidneys were aseptically removed and homogenized. Serial dilutions of the homogenates were plated on Mannitol plates and incubated overnight at 37°C. Bacterial counts were enumerated. (B) Whole-cell labeling assay with platencin. The assay was performed by using a serial dilution of platencin starting at 50 μg/ml. Platencin showed no inhibition of DNA synthesis (○) and a significant inhibition of phospholipid synthesis (●) with an IC₅₀ value of 0.19 μg/ml. Error bars show the standard deviation of two individual experiments.