[Cases of clinical and subclinical mastitis due to "D" streptococci]

Cytologic and bacteriologic investigations were carried out with a total of 364 samples of cow milk and secretion from 11 farms taken from individual quarters of the udder that have reacted positively and strongly positively with the rapid mastitis test Bernburg. It was found that in 330 of the cases there were data of clinical and subclinical mastitis of varying etiology. In 43 of the cases the causative agent (as isolated in pure cultures) proved to be "D" streptococci, giving positive reaction as judged by Schermann's criteria--from 9 cases of clinical and 34 cases of subclinical mastitis. The cell count varied from 360 000 to more than 5 million per cub. cm. Detailed studies were carried out on the cultural and biochemical properties of 31 strains of "D" streptococci, 17 strains belonging to Str. faecalis var. zymogenes, 9 strains--to Str. faecalis var. faecalis, and 5 strains--to Str. faecalis var. liquefaciens.