A recently isolated human commensal Escherichia coli ST10 clone member mediates enhanced thermotolerance and tetrathionate respiration on a P1 phage-derived IncY plasmid

Mol Microbiol. 2021 Feb;115(2):255-271. doi: 10.1111/mmi.14614. Epub 2020 Oct 12.


The ubiquitous human commensal Escherichia coli has been well investigated through its model representative E. coli K-12. In this work, we initially characterized E. coli Fec10, a recently isolated human commensal strain of phylogroup A/sequence type ST10. Compared to E. coli K-12, the 4.88 Mbp Fec10 genome is characterized by distinct single-nucleotide polymorphisms and acquisition of genomic islands. In addition, E. coli Fec10 possesses a 155.86 kbp IncY plasmid, a composite element based on phage P1. pFec10 harbours multiple cargo genes such as coding for a tetrathionate reductase and its corresponding regulatory two-component system. Among the cargo genes is also the Transmissible Locus of Protein Quality Control (TLPQC), which mediates tolerance to lethal temperatures in bacteria. The disaggregase ClpGGI of TLPQC constitutes a major determinant of the thermotolerance of E. coli Fec10. We confirmed stand-alone disaggregation activity, but observed distinct biochemical characteristics of ClpGGI-Fec10 compared to the nearly identical Pseudomonas aeruginosa ClpGGI-SG17M. Furthermore, we noted a unique contribution of ClpGGI-Fec10 to the exquisite thermotolerance of E. coli Fec10, suggesting functional differences between both disaggregases in vivo. Detection of thermotolerance in 10% of human commensal E. coli isolates hints to the successful establishment of food-borne heat-resistant strains in the human gut.

Keywords: Escherichia coli; IncY plasmid; disaggregase ClpG; phylogenetic analysis; tetrathionate respiration; thermotolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophage P1 / genetics
  • Bacteriophages / genetics
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Genome, Bacterial
  • Genomic Islands
  • Humans
  • Oxygen Consumption / physiology
  • Plasmids / genetics
  • Symbiosis / physiology
  • Thermotolerance / genetics*
  • Thermotolerance / physiology*