宫内节育器表面生物膜及细菌粘附机制的研究

Intrauterine Contraceptive Device (IUD) is one of the most commonly used contraceptive methods for women, especially in the developing country such as China where about more than 52% of women wearing IUDs in reproductive age. The insertion of IUDs provide numerous chances for bacterial adhesion and subsequent biofilm formation, causing pelvic inflammatory diseases (PIDs) and serious impairments. Both clinical and laboratory studies have shown that the use of IUDs leads to a significant increased incidence of PIDs. It involves several millions of women and is therefore considered a very important health threat. During insertion of IUDs, the vaginal and cervical bacteria can adhere to and contaminate IUD surfaces and pushing bacteria into endometrial cavity. The initial bacterial adhesion to IUD surfaces is a crucial step in the development of IUD-related PIDs. Subsequent growth of initially adhering bacteria incompletely eliminated by immunological system eventually leads to a pathogenic biofilm formation on IUDs. To date, the exact microflora of biofilm on IUD, the mechanism of bactreial adhesoion and biofilm formation on IUD are still poorly understood..In this project, we are going to first investigate the microflora of biofilm formated on IUDs using 454 pyrosequencing analysis. The morphology of biofilm on IUDs will be detected using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), and compared qualitatively and quantitatively for the effect of the influential factors of bacterial strains, IUD materials, duration of use, and with/without PID-related symptoms. Second, we are going to directly measure the adhesion forces of living bacteria to IUD materials using atomic force microscopy (AFM) for a better understanding of the mechanism of biofilm formation on IUD. We will immobilize the living bacteria isolated from removed IUDs, such as Staphylococcus epidermidis, Escherichia coli and Candida, onto a AFM cantilever and brought in contact with a IUD surface in the buffer of peptone enriched synthetic intrauterine media. Upon retract of the bacterium away from the substratum, bending of the cantilever due to the adhesion-force between bacterium and IUD substratum is measured by AFM. The results of this study will provide a better understanding of biofilm formation on IUDs and helpful informaiton for controlling IUD-related pelvic inflammatory diseases, which will make the cost-effective IUD a safety method for contraception.

宫内节育器（IUD）是我国最常用的避孕工具。IUD植入宫腔后，生殖道细菌可能粘附于其表面形成生物膜，是造成盆腔感染性疾病的重要原因之一,并可能导致严重并发症。我们前期研究发现，不同IUD材料表面粘附的生物膜数量和形态不同，细菌粘附力在生物膜形成中起关键作用。目前对IUD表面生物膜的微生物群落及形成机制的认识尚不十分清楚。本研究将①通过454高通量焦磷酸测序技术，分析研究IUD表面生物膜的微生物群落结构和多样性；②利用共聚焦激光扫描显微镜和扫描电镜，观测IUD表面细菌生物膜的三维立体结构、不同层面形态和生长变化；③利用原子力显微镜（AFM），定量检测活体细菌与IUD材料的粘附力，分析菌株、材料、宫腔液、粘附时间等因素对细菌粘附的影响，探讨IUD表面细菌粘附和生物膜形成的机制。以上研究将有助于更好的了解IUD表面生物膜的形成机制，为减少IUD表面生物膜的形成，控制IUD相关感染提供理论依据。

宫内节育器（IUD）是我国最常用的避孕工具。IUD植入宫腔后，生殖道细菌可粘附于其表面形成生物膜，是造成盆腔感染性疾病的重要原因之一,并可能导致严重并发症。我们的研究发现，不同IUD材料表面粘附的生物膜数量和形态不同，细菌粘附力在生物膜形成中起关键作用。我们的研究通过:①利用共聚焦激光扫描显微镜和扫描电镜，观测IUD表面细菌生物膜的三维立体结构、不同层面形态和生长变化；②利用原子力显微镜（AFM），定量检测活体细菌与IUD材料的粘附力，分析菌株、材料、宫腔液、粘附时间等因素对细菌粘附的影响，探讨IUDIUD表面生物膜的微生物群落,以及表面细菌粘附和生物膜形成的机制。为减少IUD表面生物膜的形成，控制IUD相关感染提供理论依据。