Intercontinental spread of promiscuous mercury-resistance transposons in environmental bacteria

Mol Microbiol. 1997 Apr;24(2):321-9. doi: 10.1046/j.1365-2958.1997.3261688.x.


We demonstrate that horizontal spread of mer operons similar to worldwide spread of antibiotic-resistance genes in medically important bacteria occurred in bacteria found in ores, soils and waters. The spread was mediated by different transposons and plasmids. Some of the spreading transposons were damaged in different ways but this did not prevent their further spread. Certain transposons are mosaics composed of segments belonging to distinct sequence types. These mosaics arose as a result of homologous and site-specific recombination. Our data suggest that the mercury-resistance operons of Gram-negative environmental bacteria can be considered as a worldwide population composed of a relatively small number of distinct recombining clones shared, at least partially, by environmental and clinical bacteria.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / genetics
  • Base Sequence
  • Carrier Proteins / genetics
  • Cation Transport Proteins*
  • DNA Transposable Elements*
  • DNA-Binding Proteins / genetics
  • Drug Resistance, Microbial / genetics
  • Gram-Negative Bacteria / genetics*
  • Gram-Negative Bacteria / metabolism*
  • Membrane Proteins / genetics
  • Mercury / metabolism*
  • Mercury / toxicity*
  • Molecular Sequence Data
  • Operon
  • Plasmids / genetics*
  • Recombination, Genetic
  • Sequence Alignment
  • Soil Microbiology
  • Water Microbiology


  • Bacterial Proteins
  • Carrier Proteins
  • Cation Transport Proteins
  • DNA Transposable Elements
  • DNA-Binding Proteins
  • Membrane Proteins
  • MerR protein, Bacteria
  • mercury transport protein, bacterial
  • Mercury

Associated data

  • GENBANK/X98999
  • GENBANK/Y08992
  • GENBANK/Y08993
  • GENBANK/Y09025
  • GENBANK/Y09026
  • GENBANK/Y09209
  • GENBANK/Y09210
  • GENBANK/Y10102
  • GENBANK/Y10103