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Microbiology Society logo Microbiology

Volume 170, Issue 7

RelQ-mediated alarmone signalling regulates growth, stress-induced biofilm formation and spore accumulation in Open Access

Abstract

The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in , a biofilm- and spore-forming pathogen that causes resilient, highly recurrent infections. The role of the SR in other processes and the effectors by which it regulates physiology are unknown. RelQ is a clostridial alarmone synthetase. Deletion of dysregulates growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type displays increased biofilm formation in the presence of sublethal stress, the Δ strain cannot upregulate biofilm production in response to stress. Deletion of slows spore accumulation in planktonic cultures but accelerates it in biofilms. This work establishes biofilm formation and spore accumulation as alarmone-mediated processes in and reveals the importance of RelQ in stress-induced biofilm regulation.

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  • Accepted:
  • Published Online:
Keyword(s): alarmone , biofilm , Clostridioides difficile and stringent response
Funding
This study was supported by the:
  • Old Dominion University
    • Principle Award Recipient: AreejMalik
  • Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases (Award 1 R15 AI156650-01)
    • Principle Award Recipient: ErinB. Purcell
  • National Science Foundation (Award 2213353)
    • Principle Award Recipient: ErinB. Purcell
© 2024 The Authors
  • This is an open-access article distributed under the terms of the Creative Commons Attribution License.
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2024-07-19
2025-07-18
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/content/journal/micro/10.1099/mic.0.001479
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RelQ-mediated alarmone signalling regulates growth, stress-induced biofilm formation and spore accumulation in Clostridioides difficile
Microbiology 170, 001479 (2024); https://doi.org/10.1099/mic.0.001479
/content/journal/micro/10.1099/mic.0.001479
/content/journal/micro/10.1099/mic.0.001479
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