Producibility of exfoliative toxin and staphylococcal coagulase types of Staphylococcus aureus strains isolated from skin infections and atopic dermatitis

Background: Strains of Staphylococcus aureus which cause staphylococcal scalded skin syndrome (SSSS) and bullous impetigo secrete exfoliative toxin (ET). Two antigenically distinct serotypes of ET, ETA and ETB, have been reported. Materials and Methods: Two hundred eighty-three strains of S. aureus isolated from impetigo, SSSS, furuncles (including furunculosis) and atopic dermatitis were examined in terms of the producibility of ET. ET serotypes and coagulase types. We examined ET production and ET serotypes using the polymerase chain reaction with the oligonucleotide primers far era and etb. Results: The incidence of ET producers was 69.4% (100/144) in impetigo, 100% (6/6) in SSSS, 2.8% (3/112) in atopic dermatitis and 0% (0/21) in furuncles. ETA alone was produced by 57 strains from impetigo and by 3 strains from atopic dermatitis, ETB alone was produced by 36 strains from impetigo and by all 6 strains from SSSS. Seven strains from impetigo produced both ETA and ETB, Most ETA producers belonged to coagulase type V and most ETB producers to coagulase type I, Impetigo strains mostly belonged to type I or V. All strains from SSSS were classified as type I. Type IV was most frequent among S. aureus isolates from furuncles. Conclusion: These results add to the epidemiological information as to ET producibility and ET serotypes of S, aureus strains isolated from impetigo, SSSS, furunculosis and atopic dermatitis. We have found that there is a relationship between the ET serotypes and the coagulase types of ET-producing strains.