What is the recommended treatment for a Trichosporon (fungus) urinary tract infection (UTI)?

Treatment of Trichosporon Urinary Tract Infection

For Trichosporon UTI, remove or replace the urinary catheter immediately and treat with voriconazole as first-line therapy, as all clinical isolates demonstrate resistance to amphotericin B and consistent susceptibility to voriconazole. 1

Immediate Management Priorities

Catheter Management

• Remove the indwelling urinary catheter if feasible, or replace it if removal is not possible 1, 2
• Catheter removal is critical because all reported Trichosporon UTI cases occur in patients with indwelling catheters for prolonged periods (typically >20 days) 1, 3
• Biofilm formation on catheters makes antifungal therapy alone insufficient without device removal 1

Antifungal Selection

• Voriconazole is the drug of choice - all Trichosporon isolates demonstrate susceptibility to voriconazole in clinical studies 1
• Do NOT use amphotericin B - all Trichosporon asahii isolates show resistance to amphotericin B 1, 4
• Itraconazole can be considered as an alternative, with majority of isolates showing susceptibility 1
• Fluconazole shows variable susceptibility (approximately 50% of isolates are sensitive), making it a less reliable option 1, 4

Confirming True Infection vs. Colonization

Before initiating antifungal therapy, establish that this represents true infection rather than colonization:

• Obtain three consecutive urine samples showing significant colony counts of the same Trichosporon species 1
• Document significant pyuria (elevated white blood cells in urine) 1
• Confirm presence of clinical symptoms (fever, dysuria, flank pain, or systemic signs of infection) 1, 2
• Consider this a complicated UTI requiring the same diagnostic rigor as other fungal UTIs 5

Risk Factor Assessment

Recognize that Trichosporon UTI occurs almost exclusively in severely ill patients with multiple predisposing factors:

• Prolonged indwelling urinary catheter use (>20 days) 3
• Broad-spectrum antibiotic use for >14 days 3
• Advanced age (mean age 60-70 years, with 55% >70 years old) 1, 3
• Comorbidities including diabetes, hypertension, chronic kidney disease, and anemia 1
• Urinary tract obstruction or nephrostomy tubes 2
• Male gender (65% of cases) 3

Treatment Duration and Monitoring

• Continue antifungal therapy until clearance of fungus from urinary tract is documented 1
• Monitor clinical recovery including resolution of fever and urinary symptoms 1, 2
• Obtain repeat urine cultures to confirm microbiological clearance 1
• The mortality rate for Trichosporon UTI is approximately 20% in ICU patients, emphasizing the need for aggressive management 3

Critical Pitfalls to Avoid

• Never use amphotericin B empirically - universal resistance makes this ineffective and delays appropriate therapy 1, 4
• Do not treat without catheter removal/replacement - antifungal therapy alone fails without addressing the biofilm source 1, 2
• Do not assume colonization - require three positive cultures with pyuria and symptoms before dismissing as colonization 1
• Avoid relying on fluconazole - only 50% susceptibility makes this unreliable as empiric therapy 1

Species Identification Considerations

• Proper species identification requires molecular methods (IGS1 sequencing) as Trichosporon species cannot be reliably differentiated by conventional methods 2
• Both T. asahii and T. loubieri cause UTI with similar clinical presentations 1, 2
• Antifungal susceptibility patterns are similar across species, with voriconazole remaining the most reliable option 1, 2