FIG. 1.
Drug susceptibilities of resistant and parent lines of T. cruzi. Mammalian-stage parasites containing the E. coli β-galactosidase gene were allowed to infect mouse 3T3 fibroblasts in microtiter plates in the presence of the indicated drug dilutions. At day 6, the growth of parasites was quantitated by the addition of the substrate CPRG and reading of the results of the colorimetric reaction at an optical density at 570 nm on an enzyme-linked immunosorbent assay reader. The Flucr line of T. cruzi, derived by long-term in vitro passage in the presence of fluconazole, was resistant to four different azole drugs in comparison to the parent line from which it was derived (a to d). There was no cross-resistance to amphotericin B (e) or benznidazole (f).