406 - Comparing the Salivary Microbiomes of Children with Pediatric COVID-19, MIS-C, and Controls from the USA and Colombia

Monday, May 1, 2023

9:30 AM – 11:30 AM ET

Poster Number: 406
Publication Number: 406.417

Brandon O'Sullivan, University of Connnecticut, Coventry, CT, United States; Katherine W. Herbst, Connecticut Children's Medical Center, Hartford, CT, United States; Alexander H. Hogan, Connecticut Children's, Hartford, CT, United States; Noah R. Schulman, Connecticut Children's Medical Center, West Hartford, CT, United States; Celina M. Porcaro, Connecticut Children's Medical Center, Cambridge, MA, United States; Michele Maltz-Matyschsyk, UCONN, Storrs, CT, United States; Justin D. Radolf, Connecticut Children's Medical Center, Avon, CT, United States; Michael Lynes, University of Connecticut, Storrs, CT, United States; Juan Carlos. Salazar, Connecticut Children's, Hartford, CT, United States; Joerg Graf, University of Connecticut, Storrs, CT, United States

Presenting Author(s)

Brandon O'Sullivan, BS

Graduate Student
University of Connnecticut
Coventry, Connecticut, United States

Background: COVID-19 is a severe respiratory illness caused by the SARS-CoV-2 virus. Although most pediatric COVID-19 cases are not serious, some children present more acutely and require inpatient treatment. Additionally, some children develop a distinct condition called Multisystem Inflammatory Syndrome in Children (MIS-C) 2-6 weeks after SARS-CoV-2 infection. MIS-C is characterized by severe whole-body inflammation and frequently is confused with Kawasaki disease, as both syndromes have high inflammatory markers and similar physical exam findings. Abnormalities in the salivary microbiome have been linked to endocarditis and diseases such as rheumatoid arthritis and diabetes.

Objective: Consequently, we sought to compare the microbiomes of different cohorts and determine if any taxa differed in relative abundance with the goal of identifying diagnostic or prognostic markers.

Design/Methods: The SARS-CoV-2 infected cohort (case) consisted of moderate to severe COVID-19, MIS-C, and asymptomatic to mild COVID-19 cases. The non-SARS-CoV-2 (control) cohort consisted of viral respiratory infections, Kawasaki disease cases, and healthy children. Traditional microbiome studies sequence only a portion of the 16S rRNA gene, such as the V4 region (~250 bp long) or the V1-V3 regions (~500 bp) and typically do not identify bacteria to the species level. Here, we utilized Intus Biosciences’ StrainID approach to amplify a ~2,500 bp region containing the entirety of the 16S rRNA gene, an internal transcribed spacer region, and a portion of the 23S rRNA gene. The amplicons were sequenced with a PacBio Sequel IIe to generate highly accurate long reads. We used DADA2 to infer Amplicon Sequence Variants (ASVs), and the QIIME2 software package and R packages (e.g., phyloseq) for the data analysis.

Results: In an initial analysis of 178 unique samples, PERMANOVA analysis with the Bray-Curtis distance metric detected significant differences in the microbiomes of the MIS-C cohort compared to all other cohorts. All cohorts differed significantly from the healthy control group. An ANCOM analysis revealed that Streptococcus mitis was significantly less abundant in the MIS-C cohort compared to non-MIS-C samples. The MIS-C cohort also could be distinguished from individual cohorts by the relative abundance of taxa. For example, Gemella sanguinis was less abundant in the MIS-C cohort than in healthy controls.

Conclusion(s):

Our results suggest that changes in the salivary microbiome can distinguish these unique clinical entities in children. Confirmation of these data with larger sample numbers is underway.