Group A streptococcal strains were isolated from the throats of 46 children 
suffering from scarlet fever. For detection of erythrogenic toxins (ETs), the 
culture supernatants were concentrated 100 times by ethanol precipitation and 
solubilisation in acetate buffer. ELISA was used to identify ETA and double 
immunodiffusion to identify ETB and ETC. The presence of the ETA gene was 
detected by a specific DNA probe. ETA (alone or in combination with ETB and/or 
ETC) was found in 51.9% of the strains, ETB (alone or in combination with ETA 
and/or ETC) in 76.9% and ETC (in combination with ETA and ETB) in 28.9%. Only 
5.8% of strains did not produce any detectable ET. In SDS-PAGE, supernatants of 
ETB-producing strains showed a pronounced band in either the region of the 
proteinase zymogen or the active proteinase. There was no correlation between 
the type of erythrogenic toxin and the serological M or T type of the producing 
strain. The mitogenic potency of culture supernatants did not differ 
significantly irrespective of the toxin type(s) present. Culture supernatants of 
strains without a detectable amount of the known ETs were highly mitogenic, 
indicating the production of other streptococcal mitogens. A correlation with 
clinical symptoms was determined with regard to exanthema and fever. Strains 
producing two or three toxins caused a more intense exanthema. Patient 
temperature was higher (greater than or equal to 38 degrees C) when the 
infecting strain produced ETB. The toxin-producing patterns of the strains of 
this study were compared with those isolated during the last epidemic outbreak 
of scarlet fever in East Germany.