Figure 4.

Effect of bump kinase inhibitors (BKIs) on Cryptosporidium parvum growth in a hollow fiber culture system. A, When BKI1294 was administered at 80 µM once per day for 4 days, there was a >6-log reduction in the C. parvum level by 24 hours after the final dose, on day 4. Similar efficacy was observed when 40 µM BKI1369 was administered once daily for 4 days. B, Unlike BKI1294 and BKI1369, 80 µM BKI1318 administered once daily had no effect on C. parvum growth in the hollow fiber model. However, coadministration of the P-glycoprotein inhibitor elacridar (80 µM) with BKI1318 generated an approximately 1-log reduction in C. parvum levels. Elacridar alone had no effect on C. parvum in the hollow fiber model. Each point represents the number of C. parvum oocysts in a single 0.5-mL sample collected at each time point from the extracapillary space.