Objective: This study examines whether the oral mycobiome of pediatric patients with newly diagnosed hematologic or oncologic malignancies differs from that of healthy children before treatment begins. Methods: The study included 117 children under 18 years of age: 67 patients and 50 healthy controls. Oral swab/rinse samples were cultured on various agar media, and fungal species were identified using conventional methods, API ID 32C, and MALDI-TOF MS. Antifungal susceptibility testing of non-albicans Candida (NAC) isolates was performed using VITEK2. Results: Yeast growth was observed in 58.2% of patients and 68% of healthy children. Candida albicans was the most frequently isolated species in both groups (43.2% in patients, 40% in controls), followed by Candida kefyr (8.95% and 6%, respectively). The patient group showed higher C. albicans colonization, while the control group had more NAC and mixed yeast colonization. Non-Candida yeasts were isolated only in healthy children (6%). However, none of these differences were statistically significant. Antifungal susceptibility testing revealed one C. kefyr isolate from a patient had a high MIC for amphotericin B (MIC=16 μg/mL). C. glabrata isolates from one patient and one healthy child were dose-dependent susceptible to fluconazole. A Candida haemolunii isolate from a healthy child had high MIC values for both fluconazole and amphotericin B (MIC=8 μg/mL). No molds were isolated. Malassezia spp. was detected in only one healthy child. Conclusion: While some differences were observed in yeast colonization rates and species distribution, the overall oral mycobiome of untreated pediatric malignancy patients did not differ significantly from that of healthy children. Further studies are required.
Özmerdiven et al. (Thu,) studied this question.