Peritonitis due to Prototheca wickerhamii in a patient undergoing chronic ambulatory peritoneal dialysis

A 72-year-old man who was undergoing chronic ambulatory peritoneal dialysis developed peritonitis due to Prototheca wickerhamii. Results of in vitro sensitivity testing revealed that the organism was sensitive to amphotericin B (MIC, 0.4 micrograms/mL) but resistant to fluconazole (MIC, greater than 80 micrograms/mL). The patient was successfully treated medically with a combination of intravenous amphotericin B and oral doxycycline.