Sharma Shivangi, Gopu Venkadesaperumal, Sivasankar Chandran, Shetty Prathapkumar Halady
Department of Food Science and Technology, Pondicherry University R. V. Nagar, Kalapet Pondicherry 605014 India
RSC Adv. 2019 Sep 11;9(49):28678-28687. doi: 10.1039/c9ra05725k. eCollection 2019 Sep 9.
Many of the Gram-negative bacteria regulate their virulence through an AHL-mediated quorum sensing (QS) mechanism. Disruption of this signaling mechanism might be a novel strategy to suppress bacterial virulence. In this report, foodborne bacterial isolates were tested for their QS-inhibitory properties using biosensor strain CV026 and the extracted potential active components were evaluated for anti-QS and antibiofilm activity against pathogenic bacteria. The cell-free supernatant of PUFSTI26 inhibited violacein production in the reporter strain and exhibited a significant reduction in extracellular virulence factors like biofilm formation, pyocyanin production, and motility of Characterization of the purified active component by gas chromatography-mass spectrometry (GC-MS) flaunted the resemblance of hydrocinnamic acid (HCA). Treatment of HCA exhibited pronounced attenuation of virulence factors. Further, the biofilm inhibitory activity was evidenced by means of confocal laser microscopy, that evidenced the repression of biofilm biomass. In addition, gene quantification analysis revealed that HCA repressed the expression of major QS-regulated genes. studies showed that HCA competitively interacts with LasR receptor protein. These results clearly indicate the anti-virulence properties of HCA extracted from of food origin. This is also the first report of the QS inhibitor activity of HCA.
许多革兰氏阴性菌通过AHL介导的群体感应(QS)机制来调节其毒力。破坏这种信号传导机制可能是一种抑制细菌毒力的新策略。在本报告中,使用生物传感器菌株CV026对食源细菌分离株的QS抑制特性进行了测试,并对提取的潜在活性成分针对病原菌的抗QS和抗生物膜活性进行了评估。PUFSTI26的无细胞上清液抑制了报告菌株中紫罗酮的产生,并使细胞外毒力因子如生物膜形成、绿脓菌素产生和运动性显著降低。通过气相色谱-质谱联用(GC-MS)对纯化的活性成分进行表征,结果显示其与氢化肉桂酸(HCA)相似。HCA处理显著减弱了毒力因子。此外,共聚焦激光显微镜证实了生物膜抑制活性,证明了生物膜生物量受到抑制。此外,基因定量分析表明HCA抑制了主要QS调控基因的表达。研究表明,HCA与LasR受体蛋白发生竞争性相互作用。这些结果清楚地表明了从食物来源中提取的HCA的抗毒力特性。这也是关于HCA的QS抑制活性的首次报道。