Conjugative DNA transfer induces the bacterial SOS response and promotes antibiotic resistance development through integron activation

PLoS Genet. 2010 Oct 21;6(10):e1001165. doi: 10.1371/journal.pgen.1001165.

Abstract

Conjugation is one mechanism for intra- and inter-species horizontal gene transfer among bacteria. Conjugative elements have been instrumental in many bacterial species to face the threat of antibiotics, by allowing them to evolve and adapt to these hostile conditions. Conjugative plasmids are transferred to plasmidless recipient cells as single-stranded DNA. We used lacZ and gfp fusions to address whether conjugation induces the SOS response and the integron integrase. The SOS response controls a series of genes responsible for DNA damage repair, which can lead to recombination and mutagenesis. In this manuscript, we show that conjugative transfer of ssDNA induces the bacterial SOS stress response, unless an anti-SOS factor is present to alleviate this response. We also show that integron integrases are up-regulated during this process, resulting in increased cassette rearrangements. Moreover, the data we obtained using broad and narrow host range plasmids strongly suggests that plasmid transfer, even abortive, can trigger chromosomal gene rearrangements and transcriptional switches in the recipient cell. Our results highlight the importance of environments concentrating disparate bacterial communities as reactors for extensive genetic adaptation of bacteria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / genetics
  • Bacteria / genetics*
  • Bacteria / metabolism
  • Conjugation, Genetic
  • DNA, Single-Stranded / genetics*
  • Drug Resistance, Microbial / genetics
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression Regulation, Bacterial
  • Gene Transfer, Horizontal
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Integrases / genetics
  • Integrases / metabolism
  • Integrons / genetics*
  • Lac Operon / genetics
  • Plasmids / genetics
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • SOS Response, Genetics / genetics*
  • Time Factors
  • Vibrio cholerae / genetics
  • Vibrio cholerae / metabolism

Substances

  • DNA, Single-Stranded
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Integrases