Association between antibodies against group B Streptococcus surface proteins and recto-vaginal colonisation during pregnancy

Sci Rep. 2017 Nov 28;7(1):16454. doi: 10.1038/s41598-017-16757-9.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Bacterial / immunology*
  • Bacterial Outer Membrane Proteins / immunology*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Pregnancy
  • Pregnancy Complications, Infectious*
  • Rectum / microbiology*
  • Streptococcal Infections / immunology*
  • Streptococcal Infections / microbiology*
  • Streptococcus agalactiae / immunology*
  • Vagina / microbiology*

Substances

  • Antibodies, Bacterial
  • Bacterial Outer Membrane Proteins
  • Immunoglobulin G