Ann Clin Microbiol.  2024 Mar;27(1):31-37. 10.5145/ACM.2024.27.1.5.

Emergence of Vanrija humicola as a pathogen of urinary tract infections in Korea

• Lee JW
• Won EJ
• Sung H
• Kim MN

• KMID: 2556216
• DOI: http://doi.org/10.5145/ACM.2024.27.1.5

Abstract

Vanrija humicola, a yeast belonging to Trichosporonaceae, is rarely pathogenic. All cases of isolation of V. humicola were retrospectively reviewed from 2021 to 2023. A total of four V. humicola were isolated from urine samples. Organisms cultured for 5 days at 25°C produced yellow, dry and cerebriform colonies, and were successfully identified as V. humicola using Bruker Biotyper MALDI-TOF. Two recent isolates were resistant to fluconazole, echinocandins, and flucytosine. In all 4 cases, V. humicola was sporadically isolated more than 14 days after admission. One case was presumed to be colonized. Of the other three cases that developed a urinary tract infection (UTI), only one with pancytopenia was treated for UTI by V. humicola with caspofungin, but expired 4 days later. V. humicola has emerged as a drug-resistant fungal pathogen of hospital-acquired UTI. Species identification and antifungal susceptibility testing of this organism are required for critical patients.

Keyword

Vanrija humicola; urine; culture; infection; antifungal susceptibility

Figure

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  Fig. 1. Culture findings of Vanrija humicola in this study. (A) After 5 days of growth on BAP, colonies are of yellow, dry and cerebriform with a fimbriate margin. (B) Microscopic examination showed budding yeasts of oval to ellipsoidal cells (2-8 × 3-12 µm) (Gram stain, ×1,000) (left side) and pseudohyphae (10-15 µm) (PAS stain, ×1,000) (right side). (C) Colonies on BAP and SDA grew more vigorously at 25℃, than at 37℃. BAP, blood agar plate; SDA, Sabouraud dextrose agar.

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