Kusari Parijat, Kusari Souvik, Lamshöft Marc, Sezgin Selahaddin, Spiteller Michael, Kayser Oliver
Department of Biochemical and Chemical Engineering, TU Dortmund, Emil-Figge-Str. 66, 44227, Dortmund, Germany.
Appl Microbiol Biotechnol. 2014 Aug;98(16):7173-83. doi: 10.1007/s00253-014-5807-3. Epub 2014 May 21.
Bacteria predominantly use quorum sensing to regulate a plethora of physiological activities such as cell-cell crosstalk, mutualism, virulence, competence, biofilm formation, and antibiotic resistance. In this study, we investigated how certain potent endophytic bacteria harbored in Cannabis sativa L. plants use quorum quenching as an antivirulence strategy to disrupt the cell-to-cell quorum sensing signals in the biosensor strain, Chromobacterium violaceum. We used a combination of high-performance liquid chromatography high-resolution mass spectrometry (HPLC-ESI-HRMS(n)) and matrix-assisted laser desorption ionization imaging high-resolution mass spectrometry (MALDI-imaging-HRMS) to first quantify and visualize the spatial distribution of the quorum sensing molecules in the biosensor strain, C. violaceum. We then showed, both quantitatively and visually in high spatial resolution, how selected endophytic bacteria of C. sativa can selectively and differentially quench the quorum sensing molecules of C. violaceum. This study provides fundamental insights into the antivirulence strategies used by endophytes in order to survive in their ecological niches. Such defense mechanisms are evolved in order to thwart the plethora of pathogens invading associated host plants in a manner that prevents the pathogens from developing resistance against the plant/endophyte bioactive secondary metabolites. This work also provides evidence towards utilizing endophytes as tools for biological control of bacterial phytopathogens. In continuation, such insights would even afford new concepts and strategies in the future for combating drug resistant bacteria by quorum-inhibiting clinical therapies.
细菌主要利用群体感应来调节大量生理活动，如细胞间串扰、共生、毒力、感受态、生物膜形成和抗生素耐药性。在本研究中，我们调查了大麻植株中某些强效内生细菌如何利用群体猝灭作为一种抗毒力策略，来破坏生物传感器菌株紫色色杆菌中的细胞间群体感应信号。我们结合使用高效液相色谱-高分辨率质谱（HPLC-ESI-HRMS(n)）和基质辅助激光解吸电离成像高分辨率质谱（MALDI-成像-HRMS），首先对生物传感器菌株紫色色杆菌中群体感应分子的空间分布进行定量和可视化。然后，我们以高空间分辨率在定量和视觉上展示了大麻的选定内生细菌如何选择性和差异性地猝灭紫色色杆菌的群体感应分子。这项研究为内生菌在其生态位中生存所采用的抗毒力策略提供了基本见解。这种防御机制的进化是为了挫败大量入侵相关宿主植物的病原体，以防止病原体对植物/内生菌生物活性次生代谢产物产生抗性。这项工作还为利用内生菌作为控制细菌性植物病原体的生物防治工具提供了证据。继续开展研究，这些见解甚至将为未来通过群体感应抑制临床疗法对抗耐药细菌提供新的概念和策略。
