# Capsular serotype in group B Streptococcus colonization and disease

> **NIH NIH R01** · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · 2022 · $702,525

## Abstract

Despite ongoing surveillance and control efforts, group B Streptococcus (GBS) remains an
important cause of infectious morbidity and mortality among newborns, as well as an increasing
cause of invasive disease in adults. GBS vaccine development is a high priority, and a
candidate conjugate polysaccharide vaccine is currently in human trials. This vaccine targets six
of the ten known GBS serotypes, based on epidemiologic studies of invasive disease as well as
rectovaginal carriage. Serotype distribution data are largely based on assays of single colonies
from clinical samples. Based on our preliminary data, we hypothesize that carriage of non-
vaccine type (NVT) GBS (serotypes VI-IX) is substantially more common than previously
realized. Additionally, invasive infections due to NVT GBS are increasing in frequency. It is not
known whether the less common GBS serotypes are intrinsically less fit than the more common
ones with respect to colonization efficiency or pathogenicity. Likewise, the importance of
recently characterized naturally occurring "capsule switch" GBS strains, in which the genetic
locus that determines capsular type has transferred from one strain to another, remains
incompletely understood. Here we propose a program of research designed to test hypotheses
regarding the prevalence of (and risk factors for) colonization and invasive infection due to NVT
GBS serotypes in human samples and to use newly developed techniques for GBS genome
manipulation to understand the role of specific capsule and non-capsule factors in colonization
fitness and pathogenesis in vivo.

## Key facts

- **NIH application ID:** 10424581
- **Project number:** 5R01AI155476-02
- **Recipient organization:** NEW YORK UNIVERSITY SCHOOL OF MEDICINE
- **Principal Investigator:** Adam Jonathan Ratner
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $702,525
- **Award type:** 5
- **Project period:** 2021-06-08 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10424581

## Citation

> US National Institutes of Health, RePORTER application 10424581, Capsular serotype in group B Streptococcus colonization and disease (5R01AI155476-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10424581. Licensed CC0.

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