title: Passive acquisition of anti-Staphylococcus aureus antibodies by newborns via transplacental transfer and breastfeeding, regardless of maternal colonization.
abstract: To investigate the transmission of anti-Staphylococcus aureus (Sa) IgG, IgG1 and IgG2 via placental transfer and the transfer of IgA via the colostrum according to maternal Sa carrier status at delivery.
  We evaluated anti-Sa IgG, IgG1 and IgG2 in maternal and cord sera and IgA in colostrum from a case (n=49, Sa+) and a control group (n=98, Sa-).
  Of the 250 parturients analyzed for this study, 49 were nasally colonized with S. aureus (prevalence of 19.6%). Ninety-eight non-colonized subjects were selected for the control group. The anti-Sa IgG, IgG1 and IgG2 levels and the IgG avidity indexes in the maternal and cord sera did not differ between the groups, with a low transfer ratio of anti-Sa IgG to the newborns in both groups. The anti-Sa IgG2 titers were significantly higher than the IgG1 titers in the maternal and cord sera. Inversely, the transfer ratios were higher for anti-Sa IgG1 compared with IgG2; however, no differences between the groups were detected. The Sa-specific IgA levels and avidity indexes in the colostrum were equivalent between groups.
  Maternal Sa nasal colonization at delivery is not associated with higher antibody levels in the mother or newborns. The high titers of anti-Sa IgG2 found in the cord serum indicate a greater reactivity with non-protein antigens, which may further contribute to the susceptibility to staphylococcal infections at birth. The presence of IgA in the colostrum with avidity to S. aureus reinforces the importance of breastfeeding shortly after birth.
authors.affiliation: Universidade Federal do Mato Grosso (UFMT), Departamento de Pediatria, Mato Grosso/MT, Brazil.|Faculdade de Medicina da Universidade de São Paulo, Departamento de Pediatria, São Paulo/SP, Brazil.
authors.forename: Maria Isabel Valdomir
authors.initials: MI
authors.lastname: Nadaf
authors.affiliation: Faculdade de Medicina da Universidade de São Paulo, Departamento de Pediatria, São Paulo/SP, Brazil.
authors.forename: Laila
authors.initials: L
authors.lastname: Lima
authors.affiliation: Universidade Federal do Mato Grosso (UFMT), Departamento de Pediatria, Mato Grosso/MT, Brazil.|Faculdade de Medicina da Universidade de São Paulo, Departamento de Pediatria, São Paulo/SP, Brazil.
authors.forename: Inês
authors.initials: I
authors.lastname: Stranieri
authors.affiliation: Universidade Federal do Mato Grosso (UFMT), Departamento de Pediatria, Mato Grosso/MT, Brazil.
authors.forename: Olga Akiko
authors.initials: OA
authors.lastname: Takano
authors.affiliation: Faculdade de Medicina da Universidade de São Paulo, Departamento de Pediatria, São Paulo/SP, Brazil.
authors.forename: Magda
authors.initials: M
authors.lastname: Carneiro-Sampaio
authors.affiliation: Faculdade de Medicina da Universidade de São Paulo, Departamento de Pediatria, São Paulo/SP, Brazil.|Hospital das Clínicas, Instituto da Criança, Laboratório de Investigação Médica (LIM-36), São Paulo/SP, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Palmeira
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D001942:Breast Feeding; D003126:Colostrum / Q000276:immunology; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D007231:Infant, Newborn; D010920:Placenta / Q000276:immunology*; D011247:Pregnancy; D012016:Reference Values; D013211:Staphylococcus aureus / Q000276:immunology* / Q000302:isolation & purification; D018709:Statistics, Nonparametric; D014470:Umbilical Cord / Q000276:immunology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G