The effect of topical antimicrobial agents on the production of toxic shock syndrome toxin-1.

Three hundred isolates of Staphylococcus aureus from wound swabs were examined for the production of toxic shock syndrome toxin 1 (TSST-1). The isolates were collected from community patients, surgical inpatients and from patients in the Regional Burns Unit, Booth Hall Children's Hospital, Manchester. The overall incidence of toxin production was 17% and there was no significant variation between the sources of the strains. All 55 TSST-1-producing strains were grown in sublethal concentrations of five topical antimicrobial compounds and the level of toxin produced was determined and compared with the amount produced in a control broth after incubation for 24 h. The effects of sublethal concentrations of the compounds on TSST-1 production were strain dependent; some compounds tended to increase production (at least four-fold) and some tended to decrease production (at least four-fold). Some of the strains showed an increase in toxin production in the presence of chlorhexidine gluconate/cetrimide solution and silver sulphadiazine cream whereas 18%, 42% and 47% of the strains showed a decrease in toxin production in the presence of povidone iodine solution, stabilised hydrogen peroxide cream and mupirocin ointment, respectively. Preliminary results suggest that silver sulphadiazine cream induces toxin formation earlier in the growth cycle.