Fachriyan Hasmi Pasaribu

Role of Hydrophobic Surface Proteins in Mediating Adherence of Group B Streptococci To Epithelial Cells

Determination of the cell-surface hydrophobicity of group B streptococci by hydrophobic interaction chromatography on phenyl-Sepharose revealed that human and bovine group B streptococcal isolates with protein surface antigens, either alone or in combination with polysaccharide antigens, were mainly hydrophobic, whereas those with polysaccharide antigens alone were mainly hydrophilic. Removal of capsular neuraminic acid enhanced, and pronase treatment reduced, surface hydrophobicity. The hydrophobic surface proteins, solubilized by mutanolysin treatment of the bacteria and isolated by hydrophobic interaction chromatography, appeared in SDS-PAGE as numerous protein bands. Staphylococcal carrier cells loaded with antibodies produced against hydrophobic surface proteins agglutinated specifically with hydrophobic group B streptococci. No agglutination reaction was observed with hydrophilic cultures. Hydrophobic group B streptococci adhered to buccal epithelial cells in significantly higher numbers than did hydrophilic cultures. The adherence of group B streptococci to epithelial cells was inhibited in the presence of isolated hydrophobic proteins and in the presence of specific antibodies produced against hydrophobic proteins. The results of this study demonstrate a close relation between the occurrence of type-specific antigens, surface hydrophobicity and the adherence of group B streptococci to epithelial cells.

Early recognition of the CAMP-reactivity in group B streptococci

Early detection of the CAMP-reactivity of group B streptococci was achieved in 5% sheep or bovine blood agar supplemented with maltose or glucose at a final concentration of 0.04% under aerobic as well as under microaerobic conditions in a candle jar. All 55 cultures of group B streptococci tested on these media yielded distinct CAMP-reactions within 8 to 10 h of incubation at 37 degrees C, allowing a more rapid recognition of these streptococci.