The Pseudomonas Aeruginosa Biofilm Dispersion Response

描述（由申请人提供）：我们实验室最近的研究表明，铜绿假单胞菌对废培养基中的可溶性有机因子有反应，诱导生物膜细胞团的分解，并导致从生物膜到浮游生活方式的转变。初步结果表明，与未诱导分散的生物膜细菌相比，这些分散的细菌对抗生素治疗明显更敏感。我们从铜绿假单胞菌（P. aeruginosa）的固定相培养物中提取并纯化了有机部分（使用葡萄糖作为唯一碳源），并对该提取物对由铜绿假单胞菌、肺炎克雷伯菌、大肠杆菌、奇迹变形杆菌、化脓性链球菌、金黄色葡萄球菌和白色念珠菌形成的生物膜进行了测试。我们还测试了该提取物与这些生物混合的物种生物膜，与对照生物膜相比，在所有情况下都检测到具有统计学意义的分散（所有分析样品的p < 0.05）。通过核磁共振、红外和质谱分析提取的有机物质的有效高效液相色谱组分，鉴定出一种小信使分子，当以纯形式合成并添加到铜绿假单胞菌的生物膜中时，复制了用纯化的废培养基提取物检测到的分散反应。我们希望对提取的有机分散诱导剂和合成的有机分散诱导剂进行测试，以研究铜绿假单胞菌中分散反应的机制。目前，我们对分散反应中蛋白质合成或裂解酶释放的作用的信息有限。在分散反应过程中，当生物膜细菌转变为浮游细胞时，我们对表型和转录调节方面发生的变化的理解也很有限。因此，本研究旨在研究提取的有机分散诱导剂在诱导生物膜细菌向浮游生活方式过渡时的生理变化中的作用。

DESCRIPTION (provided by applicant): Recent studies in our laboratory have demonstrated that P. aeruginosa respond to soluble organic factors in spent culture medium that induce the disaggregation of biofilm cell clusters and result in a switch from a biofilm to a planktonic lifestyle. Preliminary results have demonstrated that these dispersed bacteria are significantly more susceptible to antibiotic treatment when compared to biofilm bacteria that have not been induced to disperse. We have extracted and purified the organic fraction from spent stationary phase cultures of P. aeruginosa (using glucose as a sole carbon source), and have tested this extract against biofilms formed by P. aerugjnosa, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Streptococcus pyogenes, Staphylococcus aureus, and Candida albicans. We have also tested this extract against mixed species biofilms with these organisms and have detected statistically significant dispersion in all cases when compared to control biofilms (p < 0.05 in all samples assayed). Analysis of active HPLC fractions of the extracted organic material by NMR, IR and mass spectroscopy, has lead to the identification of a small messenger molecule which when synthesized in pure form and added to biofilms of P. aeruginosa, replicates the dispersion response detectable using the purified spent culture medium extract. We wish to test both the extracted organic dispersion inducer as well as the synthesized molecule to investigate the mechanism of the dispersion response in P. aeruginosa. Currently we have limited information regarding the role of protein synthesis or the release of lytic enzymes during the dispersion response. We are also limited in our understanding of the changes that occur with respect to phenotype and transcriptional regulation when biofilm bacteria transition to planktonic cells during the dispersion response. This proposal therefore, aims to investigate the role of the extracted organic dispersion inducer in inducing a change in the physiology of biofilm bacteria as they transition to a planktonic lifestyle. PUBLIC HEALTH RELEVANCE: The current application proposes work that will yield important information leading to an understanding of the biofilm dispersion response in P. aeruginosa. Findings from the proposed research are expected to lead to novel and improved strategies for the treatment of bacterial biofilms. The potential commercial possibilities for a compound that can induce dispersion in biofilms include enhanced treatment of biofilm infections, improved treatment of burns, improved removal of biofilm from surfaces, improved hygiene in hospitals, more effective cleaning products to improve health in the home, and others.