Antibodies to capsular polysaccharides of group B Streptococcus in pregnant Canadian women: relationship to colonization status and infection in the neonate.
In a cohort study of 1207 pregnant women in Alberta, Canada, the serotype distributions of vaginal-rectal group B Streptococcus (GBS) isolates were compared with all isolates from neonates with invasive GBS disease identified by population-based surveillance. Serum concentrations of Ia, Ib, II, III, and V capsular polysaccharide (CPS)-specific IgG also were determined, according to serotype of the vaginal-rectal colonizing GBS strain. GBS colonization was detected in 19.5% (235 of 1207) of women. Serotype III accounted for 20.6% (48 of 233) of colonizing strains available for typing but for 37% (27 of 73) of invasive isolates from neonates (P<.01). Maternal colonization with type III was least likely to be associated with moderate concentrations of III CPS-specific IgG. Serotype III GBS is more invasive than other serotypes in this population; this may be due, at least in part, to poor maternal type III CPS-specific antibody response.
Davies
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HD
Departments of Microbiology and Infectious Disease, Pediatrics, and Community Health Sciences and Child Health Research Unit, Alberta Children's Hospital, University of Calgary, Calgary,T2T-5C7, Canada. dele.davies@crha-health.ab.ca
Adair
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McGeer
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A
Ma
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Robertson
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Mucenski
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Kowalsky
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Tyrell
G
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Baker
C J
CJ
D000328:Adult; D000416:Alberta; D000907:Antibodies, Bacterial / Q000097:blood*; D002170:Canada; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D010298:Parity; D011135:Polysaccharides, Bacterial / Q000276:immunology; D011159:Population Surveillance; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology*; D012007:Rectum / Q000382:microbiology; D012703:Serotyping; D013290:Streptococcal Infections / Q000097:blood / Q000276:immunology* / Q000635:transmission*; D013292:Streptococcus agalactiae / Q000276:immunology* / Q000302:isolation & purification; D014621:Vagina / Q000382:microbiology
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial