Levels of toxic shock syndrome toxin-1 production among Staphylococcus aureus strains and clinical implications.

Among 250 S. aureus clinical isolates, the incidence of TSST-1 production was 18.0%. S. aureus var. hominis strains were predominant (95.6%), producing high levels of toxin in vitro, within the range of 0.6 to 4.3 micrograms/ml and exhibiting crystal violet binding with C/D pattern. No correlation was found between the level of TSST-1 production in vitro and the clinical course. Two (3.4%) of the var. bovis strains produced toxin in amounts less than 0.6 micrograms/ml and did not bind crystal violet. None of the 24 var. canis isolates produced TSST-1. Fifty five per cent of the isolates of phage group I produced TSST-1 and corresponded to 57.8% of the toxigenic strains. Two of the 250 patients developed toxic shock syndrome.