Invasive Trichosporonosis Caused by Trichosporon asahii and Other Unusual Trichosporon Species at a Medical Center in Taiwan

Background. Invasive trichosporonosis has raised attention as an opportunistic infection of immunocompromised patients in the past two decades. However, no recent case series has been reported. Methods. All patients with positive cultures for Trichosporon species from 2000 to 2008 at a medical center were evaluated. All Trichosporon species were further confirmed by analysis of intergenic spacer region of the fungal ribosomal RNA gene. In vitro susceptibility testing was performed using the broth microdilution method. Results. A positive culture for Trichosporon species was found in 43 patients. T. asahii was the most frequently species isolates (n=32, 74%), following by T. dermatis (n=5), T. montevideense (n=2), and one each of T. asteroids, T. cutaneum, T. faecale, and T. ovoides. Nineteen patients had invasive infections: 16 (84%) caused by T. asahii and one each caused be T. dermatis, T. montevideense, and T. asteroids. Among the 19 episodes of invasive trichosporonosis, 14 episodes (74%) were fungemia, three (16%) were pulmonary infection, and one (5%) each was soft tissue infection and meningitis. Most invasive infections were associated with prior antibiotics therapy (95%), use of central catheter (90%), malignancy (58%) and intensive care unit stay (50%). Azoles had good in vitro activities while amphotericin B and echinocandins were not active against Trichosporon isolates. The 30-day all-cause mortality rate was 42% and was higher among patients with malignancy (55%). Conclusions. Invasive trichosporonosis tended to develop in patients with malignancy and be associated with higher mortality. T. asahii and other unusual Trichosporon species might cause invasive trichosporonosis.