Comparative studies on group-B streptococci isolated from bovine milk samples in Thuringia and Hesse

In this study, 133 streptococci of serological group B, which were isolated from bovine milk samples in Thuringia and Hesse, were serotyped and further characterized. Serotyping of 99 group B streptococci from Thuringia revealed mainly the antigen patterns III, IV, IV/X and NT/X, and serotyping of the cultures from Hesse revealed mainly the antigen patterns IV, IV/X and NT/c alpha. The occurrence of polysaccharide- and protein-type antigens appeared to be related to various other characteristics of the bacteria. A significant relationship was observed among serotype, growth properties of the bacteria in fluid media and soft agar, and the occurrence of pigmentation. In addition, fibrinogen-binding properties of the bacteria and the ability to agglutinate rabbit erythrocytes seemed to be related to specific serotypes of the group-B streptococci. All these data were used to characterize group-B streptococcal isolates individually. This could be of importance in epidemiological studies and might help to explain the process of infection with this micro-organism.