BACKGROUND: Fungal colonization and infections remain a major cause of infection morbidity and mortality following hematopoietic stem cell transplantation (HSCT) in patients with hematological malignancies. The aim of this study was to analyze the spectrum of fungal microflora of the respiratory tract (oral cavity, pharynx, epiglottis, and sputum) in patients undergoing HSCT and to evaluate the relationship between HSCT type and incidence of mycotic colonization and infections.

MATERIAL AND METHODS: Retrospective analysis of fungal isolates collected from the respiratory tract (oral cavity, pharynx, epiglottis, and sputum) of 573 patients undergoing HSCT was performed.

RESULTS: The overall rate of fungal colonization in patients undergoing HSCT was 8.7%. Patients undergoing allogeneic HSCT were statistically significantly more often colonized (12.95%) compared to autologous HSCT recipients (4.7%). Colonizing cultures were mainly C. albicans and C. krusei, and sporadically C. glabrata, C. famata, Aspergillus spp. and Saccharomyces cerevisiae. C. albicans was the most frequent species found in isolates from the pharynx, sputum, and oral cavity collected from patients undergoing HSCT. Aspergillosis was more common after allogeneic than after autologous HSCT. The pharynx was the most frequently colonized site.

CONCLUSIONS: Allogeneic HSCT recipients are more susceptible to fungal infections compared to the autologous group. Selection of species during prophylaxis and antifungal therapy requires developing more effective prevention and treatment strategies based on new antifungal drugs and microbe-specific diagnoses.

Keywords: Allografts, Adolescent, Antifungal Agents - therapeutic use, Aspergillosis - microbiology, autografts, Candidiasis - microbiology, Hematologic Neoplasms - therapy, Hematopoietic Stem Cell Transplantation - adverse effects, Mycoses - microbiology, Respiratory Tract Infections - microbiology, Saccharomyces cerevisiae - isolation & purification, young adult