Evaluation of colonization index, molecular identification, and antifungal susceptibility pattern of species isolated from critically ill pediatric patients: A single-center study in Iran.

Background And Purpose: Given the high mortality rate of invasive candidiasis in hospitalized pediatric patients, it is crucial to establish a predictive system to achieve early diagnosis and treatment of patients who are likely to benefit from early antifungal treatment. This study aimed to assess the colonization index, species distribution, and antifungal susceptibility pattern of strains isolated from pediatric patients with high colonization index (CI).

Materials And Methods: This study was carried out at the Children's Medical Center in Tehran-Iran. In total, 661 samples were collected from 83 patients. The CI was calculated according to the descriptions of previous studies. The isolates were identified using polymerase chain reaction-based techniques. The Clinical and Laboratory Standard Institute protocol M60 was used to conduct the antifungal susceptibility test.

Results: A colonization index greater than 0.5 was confirmed in 29 cases (58% of positive samples) with two children developing candidemia. (n=53, 49.5%) was the most common species in patients with CI > 0.5. Except for acute lymphoblastic leukemia, no risk factors were linked to a high index in colonized children ( > 0.05). Twelve isolates (7.01%) were multi-azole resistant with high MICs against both isavuconazole and ravuconazole and seven strains (4.09%) were echinocandins resistant.

Conclusion: In pediatric intensive care units, patients are at risk of fungal infection, particularly candidemia. In this study, more than half of the children with positive yeast cultures had CI > 0.5, and 6.8% developed candidemia.