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Updated: Feb 18, 2026
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Association between antibodies against group B Streptococcus surface proteins and recto-vaginal colonisation during
Sonwabile Dzanibe1,2, Gaurav Kwatra1,2, Peter V Adrian1,2
1Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa.
Insights
Group B Streptococcus (GBS) recto-vaginal colonization in pregnant women can be reduced by antibodies against specific GBS surface proteins. Higher antibody levels against gbs0233 and gbs1539 were linked to a lower risk of GBS acquisition during pregnancy.
Area of Science:
- Immunology
- Microbiology
- Obstetrics
Background:
- Group B Streptococcus (GBS) recto-vaginal colonization in pregnant women is a primary risk factor for invasive GBS disease in newborns.
- Understanding factors influencing GBS acquisition during pregnancy is crucial for prevention strategies.
Purpose of the Study:
- To investigate the association between serum antibody levels against 11 GBS surface proteins and recto-vaginal GBS acquisition in pregnant women.
- To identify potential GBS surface protein targets for vaccine development.
Main Methods:
- Sera from pregnant women were collected at 20-25 weeks and ≥37 weeks gestation.
- IgG antibody titres against 11 GBS surface proteins were measured using a multiplex immunoassay.
- Recto-vaginal colonization was monitored every 4-5 weeks throughout pregnancy.
Main Results:
- Lower likelihood of GBS acquisition was observed in women with higher IgG titres against gbs0233 (adjusted OR=0.47) and gbs1539 (adjusted OR=0.44).
- Significantly higher IgG titres specific to BibA and Sip were found in GBS-colonized women compared to non-colonized women at ≥37 weeks gestation (p<0.01).
Conclusions:
- Antibodies induced by gbs0233 and gbs1539 are associated with a reduced risk of recto-vaginal GBS acquisition during pregnancy.
- These GBS surface proteins represent promising targets for developing maternal vaccines to prevent GBS colonization and subsequent neonatal disease.
Abstract:
Group B Streptococcus (GBS) recto-vaginal colonisation in pregnant women is the major risk factor for early-onset invasive GBS disease in their newborns. We aimed to determine the association between serum antibody levels against 11 GBS surface proteins and recto-vaginal acquisition of GBS colonisation during pregnancy. Sera collected from pregnant women at 20-25 weeks and ≥37 weeks of gestation age were measured for IgG titres against GBS surface proteins using a multiplex immunoassay. Women were evaluated for recto-vaginal colonisation every 4-5 weeks. We observed that the likelihood of becoming colonised with GBS during pregnancy was lower in women with IgG titres ≥200 U/mL against gbs0233 (adjusted OR = 0.47 [95% CI: 0.25-0.89], p = 0.021) and ≥85 U/mL for gbs1539 (adjusted OR = 0.44 [95% CI: 0.24-0.82], p = 0.01) when comparing between women who acquired GBS colonisation and those that remained free of GBS colonisation throughout pregnancy. IgG titres (U/mL) specific to BibA and Sip were higher in pregnant women colonised with GBS (380.19 and 223.87, respectively) compared to women with negative GBS cultures (234.42 and 186.21, respectively; p < 0.01) at ≥37 weeks gestation. Antibodies induced by gbs0233 and gbs1539 were associated with a reduced likelihood of recto-vaginal GBS acquisition during pregnancy and warrant further investigation as vaccine targets.
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