超声靶向微泡破坏对表皮葡萄球菌生物膜形态影响的研究  

Influence of ultrasound-targeted microbubble destruction on biofilm

作　　者：何年安 鲁怀伟[2] 储新民[2] 隋秀芳 赵志宏 王文平[3] 

机构地区：[1]安徽医科大学附属省立医院超声科,合肥230001 [2]安徽医科大学附属省立医院检验科,合肥230001 [3]复旦大学附属中山医院超声科

出　　处：《中华超声影像学杂志》2013年第10期905-909,共5页Chinese Journal of Ultrasonography

基　　金：国家自然科学基金（81271594）;安徽省自然科学基金（1208085MH159）

摘　　要：目的 探讨超声靶向微泡破坏（UTMD）对表皮葡萄球菌生物膜形态结构的影响,为其辅助抗生素治疗生物膜相关感染提供实验依据.方法 24 h培养的表皮葡萄球菌生物膜分组进行超声及超声＋微泡辐照实验,声强0.5～1.5 W/cm2,超声占空比为50％,辐照时间10～30 min.辐照完成后检测生物膜紫外光吸收值A570,肉眼与光学显微镜观察其形态,共聚焦激光扫描显微镜（CLSM）观察生物膜形态和其内存活菌情况,并应用扫描电子显微镜（SEM）观察辐照后的生物膜细菌表面形态.结果 对照组可见厚而致密的生物膜,未见微孔.声强0.5 W/cm2时,肉眼观察生物膜与对照组比较无明显差异,光镜下可见小的微孔（约1～10μm）,应用微泡者微孔较大.声强1.5 W/cm2时,肉眼观察到的微孔较多且较大,应用微泡时孔隙更大.与对照组比较,超声辐照或超声＋微泡组的生物膜密度有不同程度的降低,并随着声强的增大,生物膜密度下降也最多,差异有统计学意义（P＜0.05）,微泡＋超声组的生物膜密度下降又比单纯超声组明显（P＜0.05）.超声辐照后CLSM检查可见生物膜上微孔存在,未发现实验条件下的超声及UTMD具有直接杀菌作用.单纯超声辐照组和超声＋微泡组SEM检查分别可观察到细菌明显变形、皱缩和细菌表面许多小凸起.结论 超声及UTMD不具直接的杀菌作用,但可导致细菌生物膜上出现微孔,并使生物膜内的细菌表面形态发生改变,可能有利于抗生素在生物膜内的穿透,从而提高其抗菌活性.Objective To investigate whether ultrasound （US）-targeted microbubble （MB） destruction （UTMD） can influence the biofilm and bacteria in morphology.Methods Twenty-hour biofilms of Staphylococcus epidermidis RP62A were treated with US or UTMD.The acoustic intensity was 0.5-1.5W/cm2,the duty cycle was 50％ and the duration was 10 minutes.After treatment,the absorbance values （A570） of biofilms stained with the crystal violet were measured to assess the biofilm density.The biofilms were observed with macroscopy and light microscopy.The biofilms were examined by confocal laserscanning microscopy （CLSM） and scanning electron microscopy （SEM）.Results A thick and compact biofilm was observed in the untreated control group,and there were no obvious micropores in biofilms under macrology and light micrology.Although there were no significant changes under macroscopy in both biofilms treated with US only and UTMD with 0.5 W/cm2 acoustic intensity,interestingly,many micropores could be found under microscopy.The diameters of micropores increased with increasing acoustic intensity,and the micropores in biofilms treated with UTMD were bigger than those treated with US-only in the same condition of acoustic intensity （P ＜0.05）.The largest diameters of micropores were up to 1 mm in biofilms treated with UTMD using 1.5 W/cm2 （P ＜0.05）.The biofilm density （A570 value） decreased with increasing of the acoustic intensity,and the values in UTMD group of 1.5 W/cm2 were the lowest （P ＜ 0.05）.Micropores also could be observed under CLSM.There were no obvious dead bacteria in biofilms treated with US and UTMD compared with untreated control group （P ＞0.05）.Under SEM,the shape of bacteria in biofilms treated with US and UTMD became irregular,and many rounded projection could be observed in the surface of the bacteria treated with UTMD.Conclusions US and UTMD can produce micropores in biofilms,which might help to promote antibiotic activity against biofilms

关 键 词：超声检查 微气泡 生物膜 靶向治疗 

分 类 号：R445.1[医药卫生—影像医学与核医学]