637. Oropharyngeal Bacterial Community Composition Correlates with Baseline and Post-Vaccination Pneumococcal Polysaccharide Antibody Levels in HIV-Infected Subjects
Session: Poster Abstract Session: Microbiome
Thursday, October 5, 2017
Room: Poster Hall CD
Background: Streptococcus pneumoniae is the leading cause of bacterial pneumonia in HIV-infected adults, and pneumococcal vaccination is recommended in HIV. A recent study of the 13-valent pneumococcal polysaccharide conjugate vaccine (PCV13) demonstrated significant increases in pre- to 1-month post-vaccination capsular polysaccharide-specific (CPS) antibody levels in HIV-infected subjects, independent of HIV viral load or CD4 count. But significant variability was observed CPS antibody levels among subjects.

Methods: To investigate the relationship between CPS antibody levels and oropharyngeal bacterial community composition, we collected oropharyngeal swabs from 55 subjects before and after PCV13 vaccination, extracted DNA, and performed high-density (Illumina MiSeq) sequencing of the 16S rRNA gene’s V1-V2 hypervariable region. Oropharyngeal community types were identified by species-level Dirichlet-multinomial mixture modeling (Laplace approximation to model evidence) and compared to antibody levels (Kruskal-Wallis test).

Results: Two oropharyngeal community types were identified, distinguished primarily by relative abundance of Prevotella melaninogenica and several Streptococcus species. Type 1, characterized by greater abundance of Prevotella melaninogenica, Streptococcus cristatus and infantis, was associated with significantly higher baseline and post-vaccination CPS IgM/IgG; type 2, characterized by greater proportional abundance of Streptococcus salivarius and parasanguinis, with lower baseline and post-vaccination CPS IgM/IgG (Bonferroni-corrected p-values < 0.026).

Conclusion: In a cohort of HIV-infected subjects, oropharyngeal bacterial community type was correlated with CPS antibody levels pre- and post-PCV13. The interaction between the oropharyngeal bacterial microbiome (particularly non-pneumococcal Streptococcus species) and pneumococcal vaccine response warrants further investigation.

Brendan Kelly, MD, MS, Division of Infectious Diseases, University of Pennsylvania, Philadelphia, PA, Johanna Rivera, PhD, Albert Einstein College of Medicine, Bronx, NY and Liise-Anne Pirofski, MD, FIDSA, Department of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY

Disclosures:

B. Kelly, None

J. Rivera, None

L. A. Pirofski, None

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