[Group B streptococci in neonatal pathology: pathogenetic mechanism, diagnosis and prevention].

Group B streptococci have recently attracted the attention of researchers as the causative agents of human neonatal disease. They are currently encountered much more frequently than it was believed previously. Various types of adult pathogen carriers have been described; this accounts for the numerous sources and pathways of infection transmission, both vertical and horizontal. The transmission risk depends on many factors, vaginal colonization in the parturient being of special import. The level of the pathogen adhesion to the barrier epithelium is reflective of the tissue sensitivity to infection. Increased sensitivity of the vaginal epithelium to B streptococci adhesion in association with the intake of some contraceptives has been found. The adhesive activity of avirulent streptococci B strains is shown to be higher than in the virulent strains, which is especially important in mixed virus bacterial infections. The streptococcal infection of high mortality is underlain by activation of persisting avirulent streptococci B that manifest their pathogenicity as a result of the virus-specific modifications in the host cell membrane. During 1985-1987, in Leningrad Institute of Gynecology and Obstetrics over 80 strains of streptococci B were isolated, the leading serotypes being Ia/C, Ib/C, II/C, III/R. Only 54% of the studied pregnancies attended with the streptococcus carriage had a favourable neonatal outcome. The strain serotypes from maternal isolates and abortuses fully correlated. Further improvement of the laboratory diagnosis and means of the pathogen and its carriers identification is a current priority.