EFFECTS OF VARIOUS SALTS AND IRRADIATION WITH UV-LIGHT ON THE ATTACHMENT OF STAPHYLOCOCCUS-AUREUS STRAINS

We investigated the attachment of Staphylococcus aureus isolated from atopic dermatitis lesions to plastic tissue-culture coverslips. We fou nd that attachment was weaker in (rabbit) plasma with 5 or 10% NaCl an d in plasma with 5 or 10% sea salts than in the control plasma after i ncubation for 2 h (P < 0.01). The attachment was weaker still in plasm a with 10% NaCl or 10% sea salts than in the control plasma after incu bation for 24 h (P < 0.01). Plasma coagulation of four S. aureus strai ns isolated from atopic dermatitis lesions was not detected in plasma with 10% NaCl (pH 5.6) or 10% sea salts (containing 0.372% Mg2+) after incubation for 12, 24, 36 and 60 h. The attachment of S. aureus strai n cells to the coverslip in plasma was weaker after irradiation with U VA at 25 or 50 J/cm(2) (P < 0.01) and UVB at 0.5 J/cm(2) (P < 0.05) bo th of which are covered by a black cloth, than without irradiation aft er incubation for 24 h. Plasma coagulation was not detected after irra diation with UVA at 25 or 50 J/cm(2) with a black cloth cover (tempera ture reached 50 degrees C), but was detected after UVA irradiation at the same doses combined with cooling (temperature reached 22 degrees C ), after incubation for 24 h. The results suggest that the attachment of S. aureus cells isolated from atopic dermatitis lesions to the cove rslip is suppressed in the presence of 10% salts and irradiation with UVA and UVB, and that plasma coagulation of S. aureus cells isolated f rom atopic dermatitis lesions is suppressed in the presence of 10% sal ts, irradiation with UVA, and heating. (C) 1998 Elsevier Science Irela nd Ltd. All rights reserved.