Effect of subinhibitory concentrations of antibiotics on Staphylococcus aureus producing panton-valentine leukocidin / 安徽医科大学学报

ABSTRACT

Objective To explore the effect of subinhibitory concentrations (sub-MICs) of four antibiotics on pan-ton-valentine leucocidin ( PVL ) expression by Staphylococcus aureus . Methods Eight strains of PVL-positive Staphylococcus aureus were isolated by PCR. The MICs of these antibiotics were determined by constant dilution. then, PVL expression of Staphylococcus aureus was measured at different MICs of these antibiotics by ELISA. Re-sults Clindamycin, linezolid and tigecycline all could reduce the expression of PVL at 1 / 8 MIC ~ 1 / 2 MIC. after 4 and 6 hours of culturing, the relative PVL mRNA expression was reduced about 17% ~ 82% , 8% ~ 85% and 11% ~ 78% by clindamycin, linezolid and tigecycline, respectively. The protein expression of PVL was reduced by 65% and 83% under 1 / 4 and 1 / 2 MIC of clindamycin, and reduced by 40% and 61% under 1 / 4 and 1 / 2 MIC of linezolid, and reduced by 61% only at 1 / 2 MIC of tigecycline. There had no effect of vancomycin on PVL expres-sion. Conclusion The effects of four antibiotics on PVL expression at sub-MICs were different. Clindamycin and linezolid could significantly reduced PVL expression. Tigecycline colud reduced PVL expression only at high sub-MICs. Vancomycin had no effect.