ERYTHROGENIC TOXIN TYPE-A (ETA) - EPIDEMIOLOGIC ANALYSIS OF GENE DISTRIBUTION AND PROTEIN-FORMATION IN CLINICAL STREPTOCOCCUS-PYOGENES STRAINS CAUSING SCARLET FEVER AND THE STREPTOCOCCAL TOXIC SHOCK-LIKE SYNDROME (TSLS)

Erythrogenic toxin type A (ETA) is assumed to play a causative role in both scarlet fever and the streptococcal toxic shock-like syndrome (T SLS). For a molecular epidemiological analysis of the gene of erythrog enic toxin type A (speA) we used altogether 497 clinical isolates of S treptococcus pyogenes belonging to three groups: a) isolates from pati ents with scarlet fever b) isolates from cases with TSLS c) isolates f rom patients with other streptococcal infections (like otitis media, t onsillitis, impetigo) (general group) We found that less than 50% of t he scarlet fever-associated strains possessed the speA gene as compare d to 25% of the general group. Only 5 to 30% of these strains secreted the toxin under experimental conditions in very low quantities. Among strains isolated from TSLS, 67% appeared to contain the speA gene. Th e amount of ETA secreted into the medium was also extremely low. South ern hybridization patterns proved to be the same with an speA-specific probe in all three groups of streptococcal isolates (HaeIII, HindIII) . Increased occurrence of the speA gene among scarlet fever and TSLS-a ssociated strains does not seem to be sufficient to support the hypoth esis that ETA may have a causative role in both diseases since a consi derable number of strains in these groups did not possess the speA gen e.