Plasmid-borne high-level resistance to gentamicin in Enterococcus hirae, Enterococcus avium, and Enterococcus

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Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
09:00

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance

Published on: May 2, 2018

M Straut1, G de Cespédès, T Horaud

  • 1Laboratoire des Staphylocoques et des Streptocoques, Institut Pasteur, Paris, France.

Antimicrobial Agents and Chemotherapy
|May 1, 1996
PubMed

Insights

This study identified gentamicin resistance plasmids in Enterococcus species from Romania, Tunisia, and Portugal. These plasmids utilized Tn4001-like elements and, in one case, also carried tetracycline resistance genes.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Antimicrobial Resistance

Background:

  • Enterococcus species are important in clinical settings.
  • Plasmid-mediated antibiotic resistance is a growing concern.
  • Gentamicin resistance is frequently observed in Enterococcus.

Purpose of the Study:

  • To characterize plasmids encoding high-level gentamicin resistance (Gmr) in Enterococcus species.
  • To investigate the genetic elements responsible for Gmr.
  • To identify additional resistance determinants on these plasmids.

Main Methods:

  • Plasmid isolation and characterization.
  • Identification of resistance genes and mobile genetic elements.
  • Conjugation experiments (implied).

Main Results:

  • Plasmids pICC8, pIP1700, and pIP1701 from Enterococcus hirae, E. avium, and E. raffinosus harbored Gmr.
  • Gmr was associated with Tn4001-like elements or truncated versions.
  • pICC8 also contained chloramphenicol, erythromycin, and tetracycline-minocycline (TetM) resistance.
  • The tetM gene on pICC8 was located on a Tn916-like element.

Conclusions:

  • Plasmids play a significant role in the dissemination of gentamicin resistance in Enterococcus species.
  • Tn4001-like elements are key mediators of Gmr.
  • Co-selection of multiple resistance genes, including TetM, on the same plasmid is possible.

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