Comparison of Streptococcus uberis and S. infrequens. Pathogenicity for cow udder.

The pathogenicity of Streptococcus uberis and S. infrequens for cow udder was compared by experimental intramammary inoculation, mostly during the dry period. There were no significant differences between the two species according to the number and the length of infections at the subsequent lactation (Table 1). No infections could be established in lactation. The pathogenic and taxonomic implications of these results are discussed.