Natural acquired humoral immunity against serotype-specific group B Streptococcus rectovaginal colonization acquisition in pregnant women.
Group B Streptococcus (GBS) rectovaginal colonization in pregnant women is associated with invasive GBS disease in newborns, preterm delivery and stillbirths. We studied the association of GBS serotype-specific capsular polysaccharide (CPS) antibody on new acquisition and clearance of rectovaginal GBS colonization in pregnant women from 20 weeks until 37 to 40 weeks' gestation. Serum serotype-specific CPS IgG antibody concentration was measured by multiplex enzyme-linked immunosorbent assay and opsonophagocytic activity (OPA) titres. Rectovaginal swabs were evaluated for GBS colonization, using standard culture methods and serotyping by latex agglutination, at five to six weekly intervals. Higher serotype III CPS antibody concentration was associated with lower risk of rectovaginal acquisition of serotype III during pregnancy (p 0.009). Furthermore, serotype-specific OPA titres to Ia and III were higher in women who remained free of GBS colonization throughout the study compared to those who acquired the homotypic serotype (p <0.001 for both serotypes). Serum CPS IgG values of ≥1μg/mL for serotype V and ≥3μg/mL for serotypes Ia and III were significantly associated with protection against rectovaginal acquisition of the homotypic serotype. A GBS vaccine that induces sufficient capsular antibody in pregnant women, including high OPA titres, could protect against rectovaginal colonization during the latter half of pregnancy.
['Kwatra|G|G|', 'Adrian|P V|PV|', 'Shiri|T|T|', 'Buchmann|E J|EJ|', 'Cutland|C L|CL|', 'Madhi|S A|SA|']
D000328:Adult D000907:Antibodies, Bacterial D016667:Bacterial Capsules D001431:Bacteriological Techniques D002353:Carrier State D004797:Enzyme-Linked Immunosorbent Assay D005260:Female D006801:Humans D056724:Immunity, Humoral D007074:Immunoglobulin G D007231:Infant, Newborn D007841:Latex Fixation Tests D010587:Phagocytosis D011247:Pregnancy D011251:Pregnancy Complications, Infectious D012007:Rectum D065288:Serogroup D013290:Streptococcal Infections D013292:Streptococcus agalactiae D014621:Vagina D055815:Young Adult
group B Streptococcus colonization pregnant women Antibody opsonophagocytic activity