DISTRIBUTION OF SEROTYPE, VIRULENCE MARKERS AND FURTHER CHARACTERISTICS OF STREPTOCOCCUS-SUIS ISOLATES FROM PIGS

This study was designed to comparatively investigate 28 S. suis cultur es isolated from various pathological processes of pigs. All cultures could be identified biochemically and most of the cultures could be se rogrouped with specific antiserum against Lancefield's serogroup D. Se rotyping of the S. suis isolates mainly revealed capsular types 2, 1, and 22. In addition, part of the cultures, mostly those of serotype 2, reacted with monoclonal antibodies to the virulence protein muraminid ase-released protein, and, in parallel with monoclonal antibodies agai nst the virulence protein extracellular factor. Independently of serot ype and the occurrence of both virulence proteins, four cultures haema gglutinated erythrocytes from pigs, humans and rabbits. The haemagglut ination reaction appeared to be related to the surface hydrophobicity of the isolates. However, part of the cultures with hydrophobic surfac es did not haemagglutinate the available erythrocyte preparations. The surface characteristics of the S. suis isolates shown in this investi gation could be used to characterize individual isolates of S. suis th at might be of importance for epidemiological studies.