2299. Oral Microbiome of High-Risk Children: A Cohort Study

BACKGROUND: Vulnerable pediatric populations are at high risk of bloodstream infection (BSI) and sepsis, such as patients of the pediatric intensive care unit (PICU) and bone marrow transplant (BMT) wards. Previous research demonstrates that commensal gut anaerobes provide host resistance against colonization and infection with pathogens but data on other body sites is lacking. Characterization of overlap or differences in commensal microbes of the mouth can provide insight on factors that may put these populations at risk for invasive disease. METHODS: A cohort study of patients (0–18 years) at a large pediatric quaternary care center from 2017 to 2018 was conducted. Cohort group 1 children were admitted to the PICU; cohort group 2 patients were admitted to the BMT unit. Matching was by age range. Metagenomic sequencing of oral swabs and statistical analysis was performed. A retrospective review of causes of BSI in both groups from 2016 to 2018 was also conducted. RESULTS: Eighteen patients in the PICU group and 21 patients in the BMT group were identified. Common causes of BSI from 2016 to 2018 vary in each cohort (Figure 1). Unlike Enterobacteraciae, which were more common in the BMT cohort, Pseudomonas aeruginosa was a more common cause of BSI among PICU patients. When evaluating the oral microbiomes, the number of reads for Pseudomonas aeruginosa was significantly higher in the PICU group compared with the BMT group (P = 0.0019, Figure 2). CONCLUSION: Children in the PICU have a statistically significant difference in the frequency of oral colonization with Pseudomonas aeruginosa when compared with BMT patients. Unique characteristics of these populations may impact oral microbiomes of patients and their subsequent epidemiology of BSIs. Future studies should focus on preventive measures to decrease the risk of colonization with pathogenic bacteria. [Image: see text] DISCLOSURES: All authors: No reported disclosures.