低频超声对表皮葡萄球菌生物膜免疫逃逸的作用研究  

Effect of low frequency ultrasound on immune escape of Staphylococcus epidermidis biofilms

作　　者：许亚玲 刘丹如[2] 孙波[1] 董莹 XU Ya-ling, LIU Dan-ru, SUN Bo, DONG Ying(Children＇s Hospital of Fudan University, Key Laboratory of Neonatal Disease of the Health Ministry ,Shanghai 201102, Chin)

机构地区：[1]复旦大学附属儿科医院小儿呼吸急救实验室卫生部新生儿疾病重点实验室,上海201102 [2]复旦大学附属儿科医院小儿呼吸急救实验室免疫实验室,上海201102 [3]复旦大学附属儿科医院小儿呼吸急救实验室新生儿科,上海201102

出　　处：《中华医院感染学杂志》2018年第6期801-804,862,共5页Chinese Journal of Nosocomiology

基　　金：国家自然科学基金青年科学基金资助项目(81501288)

摘　　要：目的探讨低频超声干预表皮葡萄球菌生物膜(Biofilm,BF)后的变化及中性粒细胞对BF杀菌效应的改变。方法建立表皮葡萄球菌BF体外模型,采用500mW/cm^2及800mW/cm^2声强的低频脉冲超声进行干预,平板计数及结晶紫实验分别检测不同干预下BF活菌数量及生物总量的改变,将不同声强干预后的BF与兔血分离中性粒细胞体外孵育1小时,采用革兰染色法、Transwell迁移实验、流式细胞术分别检测中性粒细胞吞噬、趋化及呼吸爆发功能。结果超声干预后表皮葡萄球菌BF活菌总数与干预前差异无统计学意义;结晶紫半定量实验显示低频超声干预下的BF结构变得疏松,且BF生物总量较阴性对照组(1.57±0.11)降低(P<0.05);应用800mW/cm^2比500mW/cm^2生物总量下降更多(1.06±0.09vs.1.34±0.08,P<0.05);与阴性对照比较,500mW/cm^2、800mW/cm^2干预组中性粒细胞对BF的吞噬功能及趋化作用均增强(P<0.05);阴性对照、500mW/cm^2及800mW/cm^2干预组中性粒细胞呼吸爆发平均荧光强度为(568±53)、(637±74)和(718±59),提示超声干预效应随着声强增加而增强(P<0.05)。结论低频超声干预表皮葡萄球菌BF后BF结构变得疏松、生物总量下降,中性粒细胞对干预后BF细菌的吞噬、趋化及呼吸爆发增强。OBJECTIVE To explore the effect of low frequency ultrasound on Staphylococcus epidermidis biofilms（BF）and observe change of neutrophil activity against bactericidal effect of BF.METHODSIn vitro S.epidermidis BF models were established and exposed to low frequency ultrasound at 500 mW/cm^2 or 800 mW/cm^2 of sound intensity,the counts of viable bacteria and total biomass of BF were detected by respectively using the plate counting and crystal violet semi-quantitative test,the BF were incubated in vitro with neutrophils isolated from rabbits for 1 hour.The phagocytosis,chemotaxis and respiratory burst of neutrophils against post-treatment BF were detected by using gram staining,transwell migration test and flow cytometry,respectively.RESULTS There was no significant difference in the total counts of viable S.epidermidis BF before and after the ultrasound intervention.The crystal violet semi-quantitative test indicated that the structure of BF was loosened after the low frequency ultrasound intervention,and the total biomass of BF was significantly reduced,as compared with the control group（P0.05）;the total biomass of BF was reduced more significantly by using the sound intensity of 800 mW/cm^2 than by using the sound intensity of 500 mW/cm^2（1.06±0.09 vs.1.34±0.08,P0.05）.The phagocytosis and chemotaxis of neutrophils against BF were enhanced more significantly in the intervention group than in the control group by using the 500 mW/cm^2 and 800 mW/cm^2 of sound intensities（P0.05）;the mean fluorescence intensity of respiratory burst of neutrophils was（568±53）in the control group,（637±74）in the intervention group by using the 500 mW/cm^2 of sound intensity and（718±59）in the intervention group by using 800 mW/cm^2 of sound intensity,indicating that the ultrasound intervention effect was enhanced significantly with the increase of the sound intensity（P0.05）.CONCLUSIONAfter the low frequency ultrasound intervention,the structure of S.epidermidis BF is loosened,the total biomass is redu

关 键 词：低频超声 表皮葡萄球菌 细菌生物膜 中性粒细胞功能 

分 类 号：R378[医药卫生—病原生物学]