Quantifying the strength of quorum sensing crosstalk within microbial communities

PLoS Comput Biol. 2017 Oct 19;13(10):e1005809. doi: 10.1371/journal.pcbi.1005809. eCollection 2017 Oct.

Abstract

In multispecies microbial communities, the exchange of signals such as acyl-homoserine lactones (AHL) enables communication within and between species of Gram-negative bacteria. This process, commonly known as quorum sensing, aids in the regulation of genes crucial for the survival of species within heterogeneous populations of microbes. Although signal exchange was studied extensively in well-mixed environments, less is known about the consequences of crosstalk in spatially distributed mixtures of species. Here, signaling dynamics were measured in a spatially distributed system containing multiple strains utilizing homologous signaling systems. Crosstalk between strains containing the lux, las and rhl AHL-receptor circuits was quantified. In a distributed population of microbes, the impact of community composition on spatio-temporal dynamics was characterized and compared to simulation results using a modified reaction-diffusion model. After introducing a single term to account for crosstalk between each pair of signals, the model was able to reproduce the activation patterns observed in experiments. We quantified the robustness of signal propagation in the presence of interacting signals, finding that signaling dynamics are largely robust to interference. The ability of several wild isolates to participate in AHL-mediated signaling was investigated, revealing distinct signatures of crosstalk for each species. Our results present a route to characterize crosstalk between species and predict systems-level signaling dynamics in multispecies communities.

MeSH terms

  • Acyl-Butyrolactones / metabolism*
  • Bacterial Physiological Phenomena*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Gram-Negative Bacteria / metabolism*
  • Models, Biological*
  • Quorum Sensing*
  • Signal Transduction

Substances

  • Acyl-Butyrolactones
  • Bacterial Proteins

Grants and funding

This work was supported by Office of Naval Research award number N00014-15-1-2573 (https://www.onr.navy.mil/) and the Defense Advanced Research Project Agency Young Faculty Award D16AP00121 (https://www.darpa.mil/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.