The Use of the Serum Opacity Reaction in the Typing of Group-A Streptococci
| Autor: | Cherry A. M. Fraser, D. C. J. Bassett, Lyn C. Ball, Jean P. Widdowson, W. R. Maxted |
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| Rok vydání: | 1973 |
| Předmět: | |
| Zdroj: | Journal of Medical Microbiology. 6:83-90 |
| ISSN: | 1473-5644 0022-2615 |
| DOI: | 10.1099/00222615-6-1-83 |
| Popis: | Summary A large collection of group-A streptococci was examined for the production of opacity in horse serum and for the presence of M and T antigens. Opacity production is a constant character of certain M types and is consistently absent from the rest. Testing for opacity production is a valuable addition to the serological typing procedure especially if it is carried out first. It has proved useful in (1) reducing the number of tests with M antisera that have to be set up and (2) drawing attention to errors in M typing due to the presence of cross-reacting precipitins in typing sera. The serological specificity of the opacity factor corresponds to that of the M antigen. Inhibition of opacity production therefore provides a useful alternative method of typing strains that form the opacity factor. M antisera for opacity-producing serotypes are often of poor quality and difficult to prepare. In these circumstances, the opacity inhibition test has proved useful for preliminary identification of new M types of streptococci. |
| Databáze: | OpenAIRE |
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