A 53-year-old white woman with end-stage renal disease received a kidney transplant and was maintained on an immunosuppressive regimen. Three months later she had a fever (38.3degC) and was found to have acute renal failure. Renal transplant biopsy was performed. Periodic acid-Schiff staining of a biopsy section showed yeast cells and hyphae. The most likely diagnosis for this patient is infection with