Study for biofilm formed by Streptococcus pneumoniae and the treatment strategy

关于肺炎链球菌形成生物膜的信息仍然有限，对生物膜疾病的治疗也存在争议。为了评价肺炎链球菌生物被膜的特性，我们进行了以下研究。设计了一套研究肺炎链球菌生物被膜形成的新系统，包括新定义的生物被膜培养条件、生物被膜微量滴度测定、激光共聚焦扫描显微镜(CLSM)和扫描电子显微镜(SEM)的应用。检测不同血清型和不同药敏菌株中肺炎链球菌生物被膜的多样性。我们还研究了TIGR4菌株在有或没有抗生素处理(美罗培南)的情况下，在浮游或生物被膜条件下与抗菌素耐药性、致病性和粘附性相关的基因的体外表达。结果表明，美罗培南处理后，在生物被膜条件下，耐药相关基因和致病相关基因的表达水平较高。在本研究中，我们设计了一种新的生物被膜观察系统，我们的数据表明肺炎链球菌能够产生生物被膜，血清型和药物敏感性等许多因素都可能影响生物被膜的形成，特别是在肺炎链球菌接受抗生素治疗的情况下。所有这些发现都被认为是建立有效的生物膜疾病治疗策略的新证据的一部分。

There is still limited information about biofilm formed by Streptococcus pneumoniae, as well as the treatment of biofilm diseases is also controversial. To evaluate the characteristics of S. pneumoniae biofilm, we conducted the following study. A new system was designed to investigate the formation of S. pneumoniae biofilm, which includes newly defined biofilm culture condition, biofilm microtiter assay, and the utilities of con focal laser scanning microscopy(CLSM) and scanning electron microscope(SEM). We detected the varieties of S. pneumoniae biofilm existed in the strains with different serotypes and antimicrobial susceptibilities. We also investigated the in vitro expression of genes relevant to antimicrobial resistance, pathogenicity and adherence in the planktonic or biofilm condition, with or without antibiotic treatment(meropenem) for TIGR4 strain. As a result, the higher expression of genes relevant to antimicrobial resistance and pathogenicity was detected in the biofilm condition after meropenem treated. In this study, we designed a new biofilm observation system, and our data indicated that S. pneumoniae is capable to produce biofilm, and many factors such as serotypes, and antimicrobial susceptibilities especially when S. pneumonia is under antibiotics treatment may affect the biofilm formation. All these findings are supposed to be a part of new evidences to establish an effective biofilm diseases treatment strategy.