PROTECTION
OF GROUP B STREPTOCOCCUS TYPE-SPECIFIC ANTIBODY TO NEWBORN MICE WITH LETHAL
GBS INFECTION
Li L1, Ye HM1, Yang YH2, Shen
XZH2, Shen AD2, Huang DM1
1 The Third Hospital, Beijing
University, Beijing, China
2 Beijing Children’s Hospital, Beijing,
China
Objective: To investigate the protection of group B streptococcus (GBS)
type-specific antibody to newborn mice with lethal GBS infection.
Methods: Active immunize the pregnant mice by injecting
intra-peritoneally using GBS type III polysaccharide-tetanus toxoid
conjugate vaccine, measure the type-specific antibody of the mother mice
due to the immune response and the level of this antibody in the newborn
mice with ELISA. Then induce newborn mice lethal infection with the same
type of GBS, investigate the death rate. The group in which the pregnant
mice were injected with normal saline and the newborn mice were challenged
with lethal dose of GBS served as the group of infection control, while the
group without any procedure served as normal control.
Results: The amount of type-specific antibody in the pregnant mice
increased greatly after immunization. The geometric mean of the level of
the antibody was increased from 0.039μg/ml before immunization to 0.728μg/ml after immunization(P<0.001).
The level of this kind of antibody in newborn mice was higher than
infection control, which is 0.538μg/ml, 0.043μg/ml respectively (P<0.001),the newborn mice death rate which is 36.92% after lethal
infection was lower than infection control which is 97.01%(P<0.001).
Conclusion: The GBS type III conjugate vaccine can induce the type-specific
antibody in pregnant mice which transferred to the newborn mice and protect
them from lethal infection of GBS type III, and humoral immune plays an
important role in the anti-infection of GBS.