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An iron detection system determines bacterial swarming initiation and biofilm formation
Scientific Reports
  • Chuan-Sheng Lin, Chang Gung University
  • Yu-Huan Tsai, Chang Gung University
  • Chih-Jung Chang, Chang Gung University
  • Shun-Fu Tseng, Chang Gung University
  • Tseng-Ru Wu, Chang Gung University
  • Chia-Chen Lu, Fu Jen University
  • Ting-Shu Wu, Chang Gung Memorial Hospital
  • Jang-Jih Lu, Chang Gung Memorial Hospital
  • Jim-Tong Horng, Chang Gung University
  • Jan Martel, Chang Gung University
  • David M. Ojcius, University of the Pacific
  • Hsin-Chih Lai, Chang Gung University
  • John Ding-E. Young, Chang Gung University
David M. Ojcius: 0000-0003-1461-4495
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Iron availability affects swarming and biofilm formation in various bacterial species. However, how bacteria sense iron and coordinate swarming and biofilm formation remains unclear. Using Serratia marcescens as a model organism, we identify here a stage-specific iron-regulatory machinery comprising a two-component system (TCS) and the TCS-regulated iron chelator 2-isocyano-6,7-dihydroxycoumarin (ICDH-Coumarin) that directly senses and modulates environmental ferric iron (Fe3+) availability to determine swarming initiation and biofilm formation. We demonstrate that the two-component system RssA-RssB (RssAB) directly senses environmental ferric iron (Fe3+) and transcriptionally modulates biosynthesis of flagella and the iron chelator ICDH-Coumarin whose production requires the pvc cluster. Addition of Fe3+, or loss of ICDH-Coumarin due to pvc deletion results in prolonged RssAB signaling activation, leading to delayed swarming initiation and increased biofilm formation. We further show that ICDH-Coumarin is able to chelate Fe3+ to switch off RssAB signaling, triggering swarming initiation and biofilm reduction. Our findings reveal a novel cellular system that senses iron levels to regulate bacterial surface lifestyle.
Article Number: 36747
Citation Information
Chuan-Sheng Lin, Yu-Huan Tsai, Chih-Jung Chang, Shun-Fu Tseng, et al.. "An iron detection system determines bacterial swarming initiation and biofilm formation" Scientific Reports Vol. 6 (2016) p. 1 - 13 ISSN: 2045-2322
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