Infective endocarditis of a prosthetic mechanical valve caused by Trichosporon inkin in an immunocompetent patient: Case report.

BACKGROUND

Infective endocarditis caused by Trichosporon inkin is an exceptionally rare fungal infection, particularly in immunocompetent patients. This microorganism is part of the normal microbiota of the skin and gastrointestinal tract, but can cause invasive infections associated with prosthetic devices or complex clinical conditions. Reported cases in the literature are scarce, making it difficult to establish standardized diagnostic and therapeutic guidelines.

CASE REPORT: We report the case of an immunocompetent female patient with rheumatic fever due to which she underwent a mitral valve replacement procedure using a mechanical prosthesis, who developed infective endocarditis caused by T. inkin. The initial diagnosis was delayed due to misinterpretation as contaminant of the fungal isolate recovered. The patient developed intracerebral hemorrhage and was considered high-risk for surgical intervention; thus, medical management was pursued. The microorganism was finally identified by MALDI-TOF mass spectrometry, a validated tool for identifying Trichosporon species. The patient received voriconazole, with favorable clinical response, followed by prolonged suppressive fluconazole therapy.

CONCLUSIONS

This is the second case reported in the Americas and the fifth worldwide of T. inkin infective endocarditis in an immunocompetent patient. It highlights the importance of considering this pathogen in prosthetic valve endocarditis in cases of unusual culture results, and demonstrates the diagnostic value of MALDI-TOF. Long-term antifungal therapy with triazoles, particularly voriconazole followed by fluconazole, may be an effective alternative for patients who are not surgical candidates.