Strain identification and quorum sensing inhibition characterization of marine-derived Rhizobium sp. NAO1

A novel strategy for combating pathogens is through the ongoing development and use of anti-quorum sensing (QS) treatments such as therapeutic bacteria or their anti-QS substances. Relatively little is known about the bacteria that inhabit the open ocean and of their potential anti-pathogenic attributes; thus, in an initiative to identify these types of therapeutic bacteria, planktonic microbes from the North Atlantic Ocean were collected, isolated, cultured and screened for anti-QS activity. Screening analysis identified one such strain, Rhizobium sp. NAO1. Extracts of Rhizobium sp. NAO1 were identified via ultra-performance liquid chromatography (UPLC) analysis. They were shown to contain N-acyl homoserine lactone (AHL)-based QS analogues (in particular, the N-butyryl homoserine lactone (C4-AHL) analogue) and could disrupt biofilm formation by Pseudomonas aeruginosa PAO1. QS inhibition was confirmed using confocal scanning laser microscopy and growth curves, and it was shown to occur ...

对抗病原体的一种新型策略，是持续开发并应用抗群体感应（QS）疗法，例如治疗性细菌或其抗群体感应物质。目前学界对开阔海洋栖息细菌及其潜在抗病原体特性的了解相对匮乏；因此，为筛选此类治疗性细菌，研究人员采集、分离、培养了来自北大西洋的浮游微生物，并对其抗QS活性开展筛选。经筛选分析得到一株目标菌株——根瘤菌属（Rhizobium sp.）NAO1。通过超高效液相色谱（UPLC）分析鉴定该菌株的提取物后发现，其含有基于N-酰基高丝氨酸内酯（AHL）的QS类似物（尤以N-丁酰基高丝氨酸内酯（C4-AHL）类似物为主），且可干扰铜绿假单胞菌PAO1的生物被膜形成。研究通过共聚焦激光扫描显微镜与生长曲线验证了其QS抑制活性，且该抑制作用可发生……