From the Petri dish to the patient’s bedside: interpreting Trichosporon asahii positive urine cultures in hospitalized patients

Urinary tract infections (UTIs) are common and traditionally linked to bacteria; however, yeasts— particularly Trichosporon asahii — have emerged as opportunistic pathogens in immunocompromised and hospitalized patients. The presence of fungi may represent either colonization or infection, and the understanding of immune bases can help in this differentiation. 19 T. asahii isolates from urine cultures of hospitalized patients were analyzed and subjected to antifungal susceptibility testing. Urine samples underwent routine analysis (appearance, protein, specific gravity, pH) and flow cytometry. Clinical and sociodemographic data were obtained from electronic medical records. Results: Of the 19 patients, 11 were catheterized and 8 non-catheterized, with a predominance of males aged ≥60 years. Most were admitted to the ICU (n=13), especially in the catheterized group. A high mortality rate was observed, particularly among catheterized patients (81.1%). Urinalysis demonstrated frequent abnormalities, such as proteinuria, hematuria, and leukocyturia, suggesting an active local immune response. In association with positive cultures for T. asahii , these findings reinforce the hypothesis of active urinary tract infection. The results highlight the relevance of accurate laboratory diagnosis of this pathogen and the implementation of appropriate therapeutic strategies based on antifungal susceptibility testing, clinical expertise, and pharmacokinetic and pharmacodynamic principles. These measures are essential to optimize clinical management, improve therapeutic outcomes, and reduce mortality associated with urinary tract infections caused by multidrug-resistant T. asahii.