低频超声增强万古霉素对导管表皮葡萄球菌生物被膜影响的体内实验

Effect of low-frequency ultrasound enhanced vancomycin on catheter Staphylococcs epidermidis biofilm in vivo

目的探讨低频超声联合万古霉素对表皮葡萄球菌(S.epidermidis)RP62A生物被膜(biofi lm,BF)的影响。方法建立兔表皮葡萄球菌导管感染模型,设空白对照组,单独低频超声组,单独万古霉素组,低频超声联合万古霉素组。涂板菌落形成单位(colony-forming units,CFU)计数法计算导管细菌数;扫描电镜(scanning electron microscope,SEM)观察BF结构的改变;皮肤、心脏、肝脏及肾脏病理组织切片检查组织的炎症反应。结果单独低频超声对BF内细菌无杀灭作用,单独万古霉素能比较有效地杀灭BF内细菌,较空白对照组CFU减小,P<0.01;低频超声联合万古霉素组效果更加明显。SEM显示低频超声对BF结构无影响;与各单独作用组相比,低频超声联合万古霉素能明显地破坏BF,使其结构变得更加疏松。皮肤病理组织切片显示低频超声联合万古霉素组,皮下隧道炎症明显减轻。结论低频超声联合万古霉素能更显著地清除导管表皮葡萄球菌BF。

Objective To investigate the effect of low-frequency ultrasound combined with vancomycin on S. epidermidis RP62A strain＇s biofilm（BF）. Methods Rabbit model of S. epidermidis catheter infection was established, including blank control group, low-frequency ultrasound alone group, vancomycin alone group and low- frequency ultrasound combined with vancomycin group. Coated plate colony forming units （CFU） counting method was used to calculate the number of bacteria on catheter; Changs in the structures of BF were observed by scanning electron microscope（SEM）; pathology biopsy of skin, heart, liver and kidney to test tissue inflammation. Results Low-frequency ultrasound alone had no effect in killing BF bacteria. Vancomycin alone could eradicate BF bacteria more effectively. Compared with the control group, CFU decreased, P〈0.01; The effect of low-frequency ultrasound combined with vancomycin group was more obvious. SEM showed that the low-frequency ultrasound han no effect on the structure of BF. Compared with the alone groups, low-frequency ultrasound combined with vancomycin might significantly undermine BF, and made its structure became more loose. Conclusion Low-frequency ultrasound combined with vancomycin can more efficiently eradicate Staphylococcus epidermis BF on catheter.