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Links between S-adenosylmethionine and Agr-based quorum sensing for biofilm development in Listeria monocytogenes

Yue-Jia Lee1, Chinling Wang1

  • 1Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.

Microbiologyopen
|March 6, 2020
PubMed

Insights

S-adenosylmethionine (SAM) and Agr quorum sensing (QS) synchronize in Listeria monocytogenes, controlling nutrient availability and biofilm formation. This metabolite-QS interplay is crucial for bacterial survival and dissemination.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Molecular Biology

Background:

  • Listeria monocytogenes causes listeriosis, a severe infection with high mortality, particularly in immunocompromised individuals.
  • Biofilm formation enhances the survival and spread of L. monocytogenes in challenging environments.
  • Nutrient availability and quorum sensing (QS) are known regulators of biofilm development.

Purpose of the Study:

  • To elucidate the mechanisms governing listerial biofilm development.
  • To investigate the hypothesis that S-adenosylmethionine (SAM) and Agr-based QS signaling are synchronized in L. monocytogenes.
  • To determine how this synchronization modulates nutrient availability, extracellular polymeric substances (EPS) synthesis, and biofilm formation.

Main Methods:

  • Biofilm assays were conducted to quantify biofilm formation.
  • Quantitative real-time PCR (qRT-PCR) was used to analyze gene expression.
  • Experiments involved SAM supplementation, agr deletion, and combined treatments.

Main Results:

  • Exogenous SAM application significantly induced biofilm formation in L. monocytogenes.
  • The expression of genes involved in EPS synthesis was regulated by both SAM and Agr QS.
  • Transcriptional analysis revealed cross-regulation between the SAM synthesis methyl cycle and Agr QS systems.

Conclusions:

  • A significant interconnection exists at the transcriptional level between metabolic pathways (SAM synthesis) and QS systems in L. monocytogenes.
  • Metabolite-oriented QS, influenced by SAM, plays a critical role in bacterial biofilm development.
  • Understanding this interplay offers potential targets for controlling L. monocytogenes infections.
Keywords:
activated methyl cyclebiofilmextracellular polymeric substancespeptidoglycan synthesisquorum sensing

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