Medical Microbiology and Molecular Biology Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India.
Medical Microbiology and Molecular Biology Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India; Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra, India.
Microb Pathog. 2019 Jan;126:205-211. doi: 10.1016/j.micpath.2018.11.013. Epub 2018 Nov 10.
Enterococcus faecalis is a gram positive enteric commensal bacteria or opportunistic pathogen and its infection involves biofilm formation. Quercetin, a plant origin polyphenol was found to inhibit E. faecalis biofilm. Crystal violet assay, SEM and CLSM microscopy confirmed biofilm inhibition by quercetin. Proteomics was used to elucidate the changes occurred in bacterial cell by quercetin treatment. 2D-Electrophorosis and MALDI-TOF analysis revealed that nineteen proteins were differentially expressed in quercetin treated sample. Glycolytic pathways, protein translation-elongation pathways and protein folding pathways were under differential expression after treatment. Real Time-PCR (RT-PCR) validated the proteomic data at genomic level except for the translation elongation factor G which showed opposite data to proteomics. Protein-protein interaction networks constructed using STRING 10.0 demonstrated strong connection of translation-elongation proteins with many important proteins. The results of the comparative analysis indicate that quercetin exerts its inhibitory effect by disturbing glycolytic, protein translation-elongation and protein folding pathways. This disturbs bacterial physiology and stops transition of planktonic cells to biofilm state.
粪肠球菌是一种革兰氏阳性肠道共生菌或机会性病原体，其感染涉及生物膜的形成。槲皮素是一种植物来源的多酚，被发现可以抑制粪肠球菌的生物膜形成。结晶紫测定、扫描电子显微镜和共聚焦显微镜观察证实了槲皮素对生物膜的抑制作用。蛋白质组学用于阐明槲皮素处理后细菌细胞发生的变化。2D-电泳和 MALDI-TOF 分析显示，在槲皮素处理的样本中，有 19 种蛋白质表达差异。糖酵解途径、蛋白质翻译延伸途径和蛋白质折叠途径在处理后表达差异。实时 PCR（RT-PCR）在基因组水平上验证了蛋白质组学数据，除了翻译延伸因子 G 外，蛋白质组学数据显示相反的数据。使用 STRING 10.0 构建的蛋白质-蛋白质相互作用网络表明，翻译延伸蛋白与许多重要蛋白之间存在很强的联系。比较分析的结果表明，槲皮素通过干扰糖酵解、蛋白质翻译延伸和蛋白质折叠途径来发挥其抑制作用。这扰乱了细菌的生理机能，阻止了浮游细胞向生物膜状态的转变。
