Uromycobiome in infants and toddlers with and without urinary tract infections

Background: The bacterial components of the urobiome have been described in children, both with and without urinary tract infections (UTI). However, less is known about the pediatric uromycobiome: the community of fungi in the urine. The objectives of this study were to describe the uromycobiome in children and determine whether the uromycobiome differs between children with and without UTI.

Methods: This was a cross-sectional study of febrile children less than 3 years of age who presented to the Emergency Department and had a catheterized urine sample sent as part of clinical care. We obtained residual urine for use in this study and identified components of the uromyobiome through amplification and sequencing of the fungal ITS2 region. We then compared the uromycobiome between those with and without UTI.

Results: We included 374 children in this study (UTI = 50, no UTI = 324). Fungi were isolated from urine samples of 310 (83%) children. Fungi were identified in a higher proportion of children with UTI, compared to those without UTI (96% vs. 81%, p = 0.01). Shannon diversity index was higher in children with UTI, compared to those without (p = 0.04). Although there were differences in the most abundant taxa between children with and without UTI, there was no significant difference in beta diversity between groups.

Conclusions: Fungi were detected in the majority of catheterized urine samples from children. While a higher proportion of children with UTI had fungi in their urine, compared to children without UTI, there was no difference in the composition of these groups. A higher resolution version of the Graphical abstract is available as Supplementary information.