title: Clinical application of immunofluorescence. 3. Identification of Lancefield group B streptococci.
abstract: The identification of Lancefield group B streptococci with immunofluorescence was studied after significant differences between the precipitin and immunofluorescent results were noted. It was found that strains of group B streptococci, unlike groups A, C, and G streptococci, do not reliably react with a fluorescein isothiocyanate-labeled conjugate that contains antibodies mainly against C polysaccharide. It was assumed that the difficulty probably resulted from a blocking of the antigen-antibody reaction between the group antigen and its antibody by the S antigen located in the capsule. On the basis of this assumption, a conjugate was prepared that contained antibodies against the various S antigens of group B and it was found to be effective.
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D000942:Antigens, Bacterial; D003429:Cross Reactions; D003470:Culture Media; D005069:Evaluation Studies as Topic; D005452:Fluoresceins; D005455:Fluorescent Antibody Technique; D006801:Humans; D007106:Immune Sera; D011233:Precipitin Tests; D011817:Rabbits / Q000276:immunology; D012712:Serum Globulins; D013291:Streptococcus / Q000276:immunology*; D013861:Thiocyanates
chemical_list: D000942:Antigens, Bacterial; D003470:Culture Media; D005452:Fluoresceins; D007106:Immune Sera; D012712:Serum Globulins; D013861:Thiocyanates