Related Experiment Video
Updated: Aug 19, 2026
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
The opsonic antibody response of female rats to type III group B streptococcal immunization: a model for maternal
1Department of Pediatrics, Uniformed Services University, Bethesda, MD 20814-4799.
Group B streptococcus (GBS) remains a major cause of neonatal infection. Maternal immunization-induced GBS antibody may protect neonates from GBS disease. Since the opsonophagocytosis assay correlates well with survival in GBS infected suckling rats, we sought to determine an immunization schedule which would induce type III GBS opsonic antibody in rat dams above a predetermined level of 10 dilution-1 (dil-1). This schedule could then be used for future studies of maternal-fetal immunity. Wistar rat dams (n = 12) were given killed GBS type III using three immunization schedules (primary injection, initial booster at 7, 14 or 22 days and then weekly boosters). Opsonic GBS type III antibody and total immunoglobulin (IgG) were measured. Only the schedule with a 7-day initial booster resulted in GBS type-specific opsonic antibody consistently above 10 dil-1. The IgG (467 +/- 83 mg/100 ml) remained constant while the opsonic antibody increased significantly to 50 and 63 dil-1 (P less than 0.01 compared to day 0) after boosters on day 7 and 14 respectively. Eight pregnant dams, who received a primary immunization and boosters at 7 and 14 days, developed GBS type III opsonic antibody titers (72 dil-1) similar to non-pregnant dams and potentially adequate to protect suckling rats from GBS disease. This model may now be used to study other adjuvants, immunogens, and maternal-fetal immunity using established suckling rat models of GBS disease.
Group B streptococcus (GBS) remains a major cause of neonatal infection. Maternal immunization-induced GBS antibody may protect neonates from GBS disease. Since the opsonophagocytosis assay correlates well with survival in GBS infected suckling rats, we sought to determine an immunization schedule which would induce type III GBS opsonic antibody in rat dams above a predetermined level of 10 dilution-1 (dil-1). This schedule could then be used for future studies of maternal-fetal immunity. Wistar rat dams (n = 12) were given killed GBS type III using three immunization schedules (primary injection, initial booster at 7, 14 or 22 days and then weekly boosters). Opsonic GBS type III antibody and total immunoglobulin (IgG) were measured. Only the schedule with a 7-day initial booster resulted in GBS type-specific opsonic antibody consistently above 10 dil-1. The IgG (467 +/- 83 mg/100 ml) remained constant while the opsonic antibody increased significantly to 50 and 63 dil-1 (P less than 0.01 compared to day 0) after boosters on day 7 and 14 respectively. Eight pregnant dams, who received a primary immunization and boosters at 7 and 14 days, developed GBS type III opsonic antibody titers (72 dil-1) similar to non-pregnant dams and potentially adequate to protect suckling rats from GBS disease. This model may now be used to study other adjuvants, immunogens, and maternal-fetal immunity using established suckling rat models of GBS disease.
More Related Videos
13:00Intranasal Immunization and Milk Collection in Studies of Maternal Immunization in New Zealand White Rabbits (Oryctolagus cuniculus)
Published on: July 31, 2021
09:09Generating a Reproducible Model of Mid-Gestational Maternal Immune Activation using Poly(I:C) to Study Susceptibility and Resilience in Offspring
Published on: August 17, 2022
Related Concept Videos
01:15Transcytosis of IgG
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...
01:22Development of Immunocompetence
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...