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.%目的：观察亚抑菌浓度抗生素对金黄色葡萄球菌(金葡菌)杀白细胞素(PVL)表达的影响。方法利用 PCR筛选出8株 PVL 阳性金葡菌。常量稀释法测定克林霉素、替加环素、利奈唑胺和万古霉素最低抑菌浓度值(MIC)；荧光定量 PCR 测定前3种抗生素对 PVL 阳性金葡菌在1/8、1/4、1/2 MIC 作用下 PVL mRNA 相对变化。 ELISA 法测定4种抗生素1/4、1/2 MIC 时 PVL 蛋白含量。结果克林霉素、利奈唑胺和替加环素在1/8、1/4、1/2 MIC 时均可降低 PVL表达。 PVL mRNA 在3种抗生素作用下分别降低17%~82%、8%~85%和11%~78%；PVL 蛋白水平在1/4、1/2 MIC 克林霉素和利奈唑胺作用下，分别下降了65%和83%、40%和61%，替加环素仅1/2 MIC 时降低较明显，达64%。万古霉素不影响 PVL 表达。结论不同抗生素亚抑菌浓度时对 PVL 表达影响不同。克林霉素和利奈唑胺可明显降低PVL 表达，且呈剂量依赖性，替加环素只在较高浓度时抑制PVL 表达，万古霉素对 PVL 表达无影响。
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