A SIMPLE BLOOD AGAR PLATE MEDIUM FOR DEMONSTRATION OF THE STREPTOCOCCAL SERUM OPACITY REACTION
- 1 September 1977
- journal article
- research article
- Published by Wiley in Acta Pathologica Microbiologica Scandinavica Section B Microbiology
- Vol. 85B (5), 355-356
- https://doi.org/10.1111/j.1699-0463.1977.tb01989.x
Abstract
Blood agar plates for demonstration of the streptococcal serum opacity reaction were prepared by pouring into Petri discs 4 layers, 1 above the other, in the following sequence: agar, horse-sheep blood mixed with agar, porcine serum in agarose and agarose. Strains to be tested were streaked with a loop on the plates and a control medium was prepared as described above, but without porcine serum. After incubation for 18 h at 37.degree. C, the streptococci producing opacity factor showed greenish zones around the colonies or else no hemolysis at all on plates containing porcine serum, in contrast to a clear .beta.-hemolysis on control plates. Opacity reaction negative streptococci showed the same clear .beta.-hemolysis on both plates. Concordant results were obtained by this method and a standard method for demonstration of opacity factor.Keywords
This publication has 3 references indexed in Scilit:
- New Method for the Serological Grouping of Streptococci with Specific Antibodies Adsorbed to Protein A-Containing StaphylococciInfection and Immunity, 1973
- The Production of Opacity in Serum by Group A Streptococci and Its Relationship with the Presence of M AntigenJournal of General Microbiology, 1970