A Case of Onychomycosis Caused byRhodotorula glutinis

Abstract

Rhodotorula spp. have emerged as opportunistic pathogens, particularly in immunocompromised patients. The current study reports a case of onychomycosis caused by Rhodotorula glutinis in a 74-year-old immunocompetent female. The causative agent was identified as R. glutinis based on the pinkish-orange color; mucoid-appearing yeast colonies on Sabouraud Dextrose Agar at 25°C; morphological evaluation in the Corn Meal-Tween 80 agar; observed oval/round budding yeast at 25°C for 72 hours; no observed pseudohyphae; positive urease activity at 25°C for 4 days; and assimilation features detected by API ID 32C kit and automated Vitek Yeast Biochemical Card 2 system. Antifungal susceptibility test results were as follows: amphotericin B (MIC = 0.5 µg/mL), fluconazole (MIC = 128 µg/mL), itraconazole (MIC = 0.125 µg/mL), voriconazole (MIC = 1 µg/mL), posaconazole (MIC = 0.5 µg/mL), anidulafungin (MIC = 0.5 µg/mL), and caspofungin (MIC = 16 µg/mL). Antifungal therapy was initiated with oral itraconazole at a dose of 400 mg/day; seven-day pulse therapy was planned at intervals of three weeks. Clinical recovery was observed in the clinical evaluation of the patient before the start of the third cure. Although R. glutinis has rarely been reported as the causative agent of onychomycosis, it should be considered.

Rhodotorula species infections in humans: A systematic review

“…No additional studies were found by hand‐screening of the included articles’ references. Finally, 111 met the criteria . Additional information was kindly provided by the corresponding author of one study .…”

Reversible naftifine-induced carotenoid depigmentation in Rhodotorula mucilaginosa (A. Jörg.) F.C. Harrison causing onychomycosis

“…Candida species are the most frequent among the yeasts 7 . Other yeasts accepted in recent years as causative agents of onychomycosis are Rhodotorula mucilaginosa 9 , R. minuta 10 and R. glutinis 11 . Several authors have isolated Rhodotorula from ecosystems and environments 12 – 15 , humans 16 – 18 and animals 13 .…”

“…Thus, in vitro susceptibility tests demonstrated that R. mucilaginosa is sensitive to low concentrations of amphotericin B and 5-flucytosine and resistant to high concentrations of fluconazole, itraconazole, voriconazole and terbinafine 9 . Additionally, in the case of R. glutinis , minimum inhibitory concentrations (MIC) vary depending on the antifungal drug: 0.125 μ g/mL for itraconazole; 0.5 μ g/mL for amphotericin B, anidulafungin and posaconazole; 1 μ g/mL for voriconazole; 16 μ g/mL for caspofungin and 128 μ g/mL for fluconazole 11 . Overall, for humans the use of antifungals against Rhodotorula infections is still controversial because in vitro some are inactive against the majority of clinical isolates of Rhodotorula spp.…”

A successful management of fungal peritonitis caused by Rhodotorula glutinis in CAPD patient, coincident with onychomycosis by Penicillium sp: Case report

“…Oral itraconazole was given for her antifungal therapy and clinical recovery was detected. [10] There are no studies that reported the correlation between other sites of fungal infection such as onychomycosis with the incidence of fungal peritonitis in PD patients. Data from HD patients, the prevalence of onychomycosis was higher than in the general population.…”

“…infections could occur at any site of the body, [ 8 ] and Rhodotorula glutinis was never reported as an etiology of onychomycosis. [ 10 ] We report a case of fungal peritonitis in a PD patient due to R glutinis , his Tenckhoff catheter was removed and reinserted simultaneously, and PD could still be maintained. He also had another site of fungal infection in his toenail, which was a possible risk factor for fungal peritonitis.…”