万古霉素对hVISA生物膜构成的影响  

Characterization of biofilm formation by heterogeneous VISA exposed to vancomycin

作　　者：桑瑞瑞 郜梦露 夏金星 沈继龙[2] 徐元宏[1,2] Sang Ruirui;Gao Menglu;Xia Jinxing(Dept of Laboratory,The First Afiliated Hospital of Anhui Medical University,Hefei 230022)

机构地区：[1]安徽医科大学第一附属医院检验科,合肥230022 [2]安徽医科大学人兽共患病安徽省重点实验室,合肥230022

出　　处：《安徽医科大学学报》2019年第12期1876-1881,共6页Acta Universitatis Medicinalis Anhui

基　　金：国家自然科学基金(编号:81171606)

摘　　要：目的探讨万古霉素对异质性万古霉素中介金黄色葡萄球菌(hVISA)生物膜构成的影响,及其与万古霉素治疗hVISA失败率高的关系。方法将临床菌株hVISA(05307)和Mu3(ATCC 700698,hVISA的参考菌株)暴露于不同浓度的万古霉素。单独的肉汤和不含抗生素的细菌悬浮液分别作为阴性和阳性对照组。使用结晶紫(CV)染色测量hVISA的生物膜总量,并且使用激光共聚焦显微镜(CLSM)观察生物膜的三维结构。细胞外基质(ECM)中的蛋白质组分,细胞外多糖黏附素(PIA)和细胞外DNA(eDNA)分别采用直接和间接的方法定量.结果与阳性对照组相比,只有1倍最低抑菌浓度(MIC)的万古霉素处理组增加了hVISA的生物膜总量。另外,各组提取的ECM中PC和蛋白质的表达没有明显区别。加入DNase I处理后,1×MIC万古霉素处理组的生物膜总量被显著抑制到与万古霉素未处理组相近的水平。结论1×MIC的万古霉素诱导的eDNA释放是万古霉素增强hVISA生物膜形成主要因素,这可能是万古霉素治疗hVISA感染失败率高的原因之一。Objective To investigate the effect of vancomycin on the biofilm formation by heterogeneous vancomy-cin-intermediate Staphylococcus aureus(hVISA),and its association with the high frequeney of failure in vancomy-cin treatment failure of hVISA.Methods A clinical strain of hVISA(05307)and the Mu3(ATCC 700698,hVISA reference strain)were exposed to different concentrations of vancomyein.The broth alone and the bacterial suspen-sion without antibiotics were served as negative and positive controls,respectively.The biofilm biomass of hVISA was measured using the crystal violet(CV)staining and visualized under the Confocal laser scanning microscopy(CLSM).Protein components,polysaccharide intracellular adhesin(PIA)and extracellular DNA(eDNA)in the extracellular matrices(ECM)were quantified directly and irldirectly,respectively.Results One fold minimal in-hibitory concentration(MIC)vanconycin enhanced the biofilm formation by hVISA.Additionally,no significant in-crease of PIA and protein components production were observed.V ancomycin-enhanced biofilm formation was re-markably suppressed to a level similar to vancomycin-untrealed cells following DNaseI administration.Conclusion The 1 x MIC vancomyein induced release of eDNAs is an essential factor for vancomyein-enhanced biofilm forma-tion of hVISA,which may help account for the failure of vancomycin treatment in hVISA infections.

关 键 词：金黄色葡萄球菌 生物膜 异质性万古霉素中介金黄色葡萄球菌 万古霉素 细胞外基质 

分 类 号：R446.5[医药卫生—诊断学]