Biochemical and serological properties of Streptococcus uberis

The Strep-Zym identification system, a combination of 23 enzymatic tests, allowed a rapid biochemical characterization of Streptococcus uberis. The biochemical profiles of the S. uberis cultures clearly differed from those of S. agalactiae and S. dysgalactiae. Serological grouping of S. uberis revealed polysaccharide antigens of groups E, G, P and U. Some cultures of S. uberis demonstrated CAMP-like synergistic hemolytic activities on sheep blood agar and reacted specifically with the lectins of Helix pomatia and Dolichos biflorus. The occurrence of group polysaccharides, CAMP-like reactivities, and the lectin agglutination reactions were obviously not related to each other or to any of the biochemical properties. These reactions, possibly of importance as virulence factors, might serve as epidemiological markers.