[Comparative analysis of antigenic preparations made from noncapsular strains of Pneumococcus].

Nonencapsulated strains obtained by subculturing Streptococcus pneumoniae in a medium containing 0.5% of bile have been shown to possess a number of morphological and cultural features. The preparations obtained from the biomass of these strains by sonication have been found to possess antigenic, immunogenic and protective properties and to be specific to S. pneumoniae. The data obtained in this investigation may be considered indicative of the necessity for further study of these preparations with a view to their use for the analysis of serum samples taken from patients with bronchopulmonary diseases by means of enzyme immunoassay.