鲍曼不动杆菌生物膜形成是其耐药及传播的主要原因。近年的研究表明，碳储存调控因子（CsrA）通过与靶mRNAs 5'非翻译区结合，调控多种细菌的运动、毒力及生物膜形成。我们先前的研究已证实CsrA存在于鲍曼不动杆菌，且csrA mRNA表达量与该菌产生物膜的能力显著的负相关，但机制未明。我们前期的研究工作也显示：鲍曼不动杆菌编码细胞表面蛋白oprD-like和dcaP-like mRNAs上存在多个CsrA结合位点。CsrA很可能通过这些表面蛋白而负性调控鲍曼不动杆菌生物膜形成。本课题拟利用Red重组系统、5'RACE、Toeprint法、EMSA等获得CsrA调控oprD-like和dcaP-like的直接证据，从而明确CsrA在鲍曼不动杆菌生物膜形成中调控oprD-like和dcaP-like的具体机制，为确定CsrA作为抗细菌生物膜治疗新靶点及预防鲍曼不动杆菌传播提供坚实的实验依据。

Biofilm formation of Acinetobacter baumannii is the major reason for its resistance and dissemination. The cell surface proteins play an important role in bacterial adhesion and biofilm formation. Recent studies showed that the carbon storage regulator (CsrA) is an RNA binding protein, which regulates mobility, virulence and biofilm formation through binding to the 5'untranslated region of the target mRNAs in various eubacteria.Our preliminary studies confirmed CsrA was present in Acinetobacter baumannii, and there was a significant negative correlation between the levels of csrA mRNA and the capacity of biofilm formation of Acinetobacter baumanni.The mechanism is unknown. and our preliminary studies showed that the mRNAs of oprD-like and dcaP-like have multiple conserved sequences of the CsrA binding sites in Acinetobacter baumannii. it is likely that CsrA negatively regulates biofilm formation of Acinetobacter baumannii by these surface proteins. Based on preliminary studies, the mRNAs of oprD-like and dcaP-like directly regulated by CsrA will be identified by Red recombination, 5'RACE, Toeprint assay and RNA gel mobility shift assay. The project will yield novel insight into the CsrA regulatory networks in biofilm information of Acinetobacter baumannii.