Abstract
A grouping of 138 strains of hemolytic streptococci based on differences in dye-sensitiveness and in final hydrogen-ion concentration of cultures is presented. Three groups are distinguished; (1) human parasitic strains, defined by a final pH range of 5.2 to 5.0 and by failure to reduce methylene blue (1:5000) in milk, (2) bovine strains parasitic in the udder, characterized by a final pH range of 4.5 to 4.2 and by failure to reduce methylene blue (1:5000) in milk, (3) saprophytic strains, characterized by a final pH range of 4.5 to 4.2 and by ability to reduce methylene blue. Methylene blue was bactericidal for the strains of hemolytic streptococci that fail to reduce it, but neither bacteriostatic nor bactericidal for the strains that caused its reduction.
Full Text
The Full Text of this article is available as a PDF (301.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Avery O. T., Cullen G. E. THE USE OF THE FINAL HYDROGEN ION CONCENTRATION IN DIFFERENTIATION OF STREPTOCOCCUS HAEMOLYTICUS OF HUMAN AND BOVINE TYPES. J Exp Med. 1919 Jan 31;29(2):215–234. doi: 10.1084/jem.29.2.215. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones F. S. STREPTOCOCCI OCCURRING IN SOUR MILK. J Exp Med. 1921 Jan 1;33(1):13–24. doi: 10.1084/jem.33.1.13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sherman J. M., Albus W. R. Some Characters which Differentiate the Lactic-acid Streptococcus from Streptococci of the Pyogenes Type Occurring in Milk. J Bacteriol. 1918 Mar;3(2):153–174. doi: 10.1128/jb.3.2.153-174.1918. [DOI] [PMC free article] [PubMed] [Google Scholar]