[Serotypes and antibody levels of group B streptococci in pregnant women].

Group B streptococcus were isolated from 1404 pregnant out-patient women in the Department of Obstetrics and Gynecology, St. Marianna University School of Medicine, from June 1, 1992 to May 31, 2001. Serotype of 187 (13.3%) fresh isolates of GBS was determined by using hemolytic streptococcus-typing immune sera (Denka Seiken, Tokyo, Japan). With these strains there were 59 (31.6%), 46 (26.6%), 19 (10.2%), 16 (8.6%), 16 (8.6%), 12 (6.4%) and 3 (1.6%) indicating that their types were VIII, VI, III, Ia, V, Ib and II respectively. Also, bacterial agglutination reaction was employed for detection of titer to GBS in pregnant women serum. Positive reaction showed in 31 (57.4%) samples but 23 (42.6%) samples were not seen in this essay. It is assumed that the high antibody levels in pregnant women serum plays an important role as an in vivo defence factor in neonatal infection by GBS.