Comparison of the characteristics of patients with invasive infections and noninvasive infections caused by Trichosporon asahii.

We performed retrospective study to identify the characteristics of invasive Trichosporon asahii infection. A total of 102 patients with T. asahii were identified including 18 (18%) with invasive infection. Invasive infection was associated with indwelling central venous catheter (94% vs 54%, P = .001), prior antifungal agent use (50% vs 18%, P = .01), hematologic malignancy (33% vs 7%, P = .006), and end-stage renal disease (28% vs 7%, P = .02). Patients with invasive infections had higher in-hospital mortality than patients with noninvasive infections (61% vs 27%, P = .006). Those with the above risk factors should be monitored for the development of invasive T. asahii infection. LAY SUMMARY: Patients with indwelling central venous catheter, prior antifungal agent use, hematologic malignancy, and end-stage renal disease were associated with invasive Trichosporon asahii infection. Patients with invasive infections had higher in-hospital mortality than patients without invasive infection.

The development of animal infection models and antifungal efficacy assays against clinical isolates of Trichosporon asahii, T. asteroides and T. inkin.

The present study developed Galleria mellonella and murine infection models for the study of Trichosporon infections. The utility of the developed animal models was demonstrated through the assessment of virulence and antifungal efficacy for 7 clinical isolates of Trichosporon asahii, T. asteroides and T. inkin. The susceptibility of the Trichosporon isolates to several common antifungal drugs was tested in vitro using the broth microdilution and the E-test methods. The E-test method depicted a lower minimal inhibitory concentration (MIC) for amphotericin and a slightly higher MIC for caspofungin, while MICs observed for the azoles were different but comparable between both methods. All three Trichosporon species established infection in both the G. mellonella and immunosuppressed murine models. Species and strain dependent differences were observed in both the G. mellonella and murine models. T. asahii was demonstrated to be more virulent than the other 2 species in both animal hosts. Significant differences in virulence were observed between strains for T. asteroides in the murine model. In both animal models, fluconazole and voriconazole were able to improve the survival of the animals compared to the untreated control groups infected with any of the 3 Trichosporon species. In G. mellonella, amphotericin was not able to reduce mortality in any of the 3 species. In contrast, amphotericin was able to reduce murine mortality in the T. asahii or T. inkin models, respectively. Hence, the developed animal infection models can be directly applicable to the future deeper investigation of the molecular determinants of Trichosporon virulence and antifungal resistance.

Microbiologically documented fungal infections in pediatric patients with acute myeloid leukemia: 12.5-year experience at a single institution.

The primary objective of this study was to determine the incidence and types of microbiologically documented fungal infections in 56 children with acute myeloid leukemia admitted to Wolfson Children's Hospital. The secondary objective was to determine the factors that may affect the treatment and outcome of these infections, such as antifungal prophylaxis, absolute neutrophil count, age, and phase of therapy. Medical records were reviewed from January 1, 2000 to July 31, 2012. Over the 12.5-year study period, there were 11 patients with 25 episodes of fungal infections. Adolescents with acute myeloid leukemia (13 to 18 y old) represented 48% of the population. Children less than 3 years of age and between 3 and 12 years of age represented one quarter each. None of the patients less than 3 years of age developed fungal infections, whereas 64% of the adolescents did (P=0.01). Blood-borne infections were the most common site of infection (44%). Eighty-four percent of infections occurred in neutropenic patients. The mortality rate in the overall cohort was 28%. Patients with fungal infections had increased mortality rate of 55%. Overall candidiasis and aspergillosis were the major pathogens (28% each), although there have been no occurrences of Aspergillus sp. since 2005. On the basis of the results of our study, it would be prudent to provide antifungal coverage for both these pathogens, such as with voriconazole or echinocandins over fluconazole.