Objective To investigate the effect of sub-minimal inhibitory concentration (sub-MIC) ceftaroline on the biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA) isolates and provide the theory support for clinical treatment of antibiotics.Methods The MICs of anitibiotics to MRSA isolates were detected by broth microdilution method.The effect of sub-MIC ceftaroline on the biofilm formation of MRSA isolates was determined by using 96-crystal violet staining.The production of extracellular polymeric substances was detected by phenol-sulfuric acid method.The expression of icaA gene was analyzed by Real-Time PCR amplification.Results Ten MRSA strains were high resistant to most of the tested antibiotics,whereas they were all sensitive to nitrofurantoin,vancomycin and ceftaroline.Sub-MIC ceftaroline could significantly induce the biofilm formation of seven MRSA strains.In addition,sub-MIC ceftaroline could increase the production of extracellular polymeric substances and icaA gene expression of MRSA strains.Conclusions Sub-MIC ceftaroline might increase the production of extracellular polymeric substances by inducing the icaA gene expression,and then result in the enhancement of MRSA biofilm formation.%目的 探讨亚抑菌浓度头孢洛林对耐甲氧西林金黄色葡萄球菌生物膜形成能力的影响,为抗菌药物的临床使用提供理论依据.方法 金黄色葡萄球菌抑菌浓度(MIC)检测采用微量肉汤稀释法,亚-MIC头孢洛林对细菌生物膜形成能力的影响采用96孔板结晶紫染色法,胞外多糖的检测采用苯酚-硫酸法,icaA基因的表达采用荧光定量PCR扩增.结果 10株MRSA菌株对大部分抗菌药物具有较高耐药性,而对呋喃妥因、万古霉素和头孢洛林完全敏感.亚-MIC头孢洛林对7株MRSA菌株的生物膜形成具有显著诱导作用.此外,亚-MIC头孢洛林能增加MRSA菌株胞外多糖的产生和icaA基因的表达.结论 亚-MIC头孢洛林可能通过诱导icaA基因表达而增加胞外多糖的产生,从而导致细菌生物膜形成能力增强.
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