Trichosporon austroamericanum Infection After Kidney Transplantation: A Six Case Series Revealing a Newly Recognized Pathogen with Allograft Tropism.

Trichosporon austroamericanum, described in 2024, closely related to T. inkin, expands the spectrum of Trichosporon species that cause life-threatening infections in immunocompromised patients, particularly solid organ transplant recipients. We describe the first case series of Trichosporon austroamericanum infections at kidney transplant (KT) surgical sites between 2022 and 2025 in Marseille, including two involving granulomatous kidney allograft infiltration, a previously unreported complication. Five patients presented with inflammatory surgical wounds and abscesses at the KT site within 6 to 16 weeks after KT. Four patients were successfully treated with surgical drainage and voriconazole. Two developed severe invasive infection with allograft fungal infiltration. The first developed fungemia and recurrent abdominal abscesses; the infection progressed despite therapy, with emerging multidrug resistance, ultimately resulting in death. The second presented with a late infection, 11 months post-KT, characterized by mycotic arteritis and septic emboli, requiring emergency transplantectomy. Despite 6 months of azole therapy, treatment was discontinued for severe hepatotoxicity progressing to cirrhosis, and the patient subsequently died from septic shock with acute-on-chronic liver failure. Environmental investigations identified a possible operating theatre contamination, although a definitive source could not be established. These cases highlight the pathogenic potential of T. austroamericanum, presenting as KT site infection, with possible allograft infiltration. Management should include early antifungal therapy-voriconazole as first-line for at least 4 weeks-combined with surgical debridement, and if possible, immunosuppression reduction.