Enterotoxin production by strains of Staphylococcus aureus isolated from clinical specimens of human and animal origin and from healthy human carriers was investigated. All nine patients admitted to hospital with symptoms of toxic shock syndrome (TSS) yielded enterotoxin-producing strains of S. aureus. Eight of these produced staphylococcal enterotoxin F (SEF). A significantly smaller proportion of strains (42% of 50 strains tested) isolated from other clinical specimens of hospitalized patients produced SEF. Production of SEF by strains isolated from clinical specimens of animal origin (48 strains) was not observed. Twenty-nine per cent of 24 S. aureus strains isolated from noses of hospital staff produced SEF. This result was not significantly different from that obtained from strains isolated from clinical specimens other than TSS. A similar percentage of strains isolated from healthy human carriers outside hospital produced SEF (25% of 24 strains tested).
The results indicated that enterotoxin production, especially that of SEF. is associated with S. aureus isolated from patients suspected of TSS. There was no indication of an association between S. aureus isolated from other staphylococcal infections and SEF production.
All strains were phage typed and 79%, of the strains belonging to the international phage-group I produced SEF. All strains lysed by phage 187 were found to produce SEF.