A truncated Tn916-like element in a clinical isolate of Enterococcus faecium

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A Duplex Digital PCR Assay for Simultaneous Quantification of the Enterococcus spp. and the Human Fecal-associated HF183 Marker in Waters
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A Duplex Digital PCR Assay for Simultaneous Quantification of the Enterococcus spp. and the Human Fecal-associated HF183 Marker in Waters

Published on: March 9, 2016

H M Fletcher1, L Daneo-Moore

  • 1Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.

Plasmid
|March 1, 1992
PubMed

Insights

This study characterizes plasmid pKQ1 from Enterococcus faecium, revealing a modified Tn916 element carrying tetM and a Tn917-like element conferring erythromycin resistance. Transposition of these resistance genes was not observed in tested bacteria.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Enterococcus faecium is a significant opportunistic pathogen.
  • Antibiotic resistance in bacteria is a growing public health concern.
  • Plasmids play a crucial role in the dissemination of antibiotic resistance genes.

Purpose of the Study:

  • To characterize the genetic structure of the nonconjugative plasmid pKQ1.
  • To investigate the organization of antibiotic resistance determinants within pKQ1.
  • To assess the transposition potential of resistance elements on pKQ1.

Main Methods:

  • Plasmid DNA isolation and characterization.
  • Restriction enzyme digestion and fragment analysis (HincII, ClaI).
  • Bacterial transformation experiments (Bacillus subtilis, Streptococcus sanguis).

Main Results:

  • Plasmid pKQ1 (58.7 kb) harbors tetM and an erythromycin resistance (erm) determinant.
  • pKQ1 contains a truncated Tn916-like element with a modified B fragment and a missing C fragment.
  • A Tn917-like element, similar in size to Tn917, is adjacent to the truncated Tn916-like element.
  • No zygotically induced transposition of tetM or the Tn917-like element was detected in transformed B. subtilis or S. sanguis.

Conclusions:

  • Plasmid pKQ1 possesses a unique mosaic structure of Tn916 and Tn917-like elements.
  • The tetM and erm determinants on pKQ1 appear to be stably maintained and do not exhibit transposition under the tested conditions.
  • Understanding the genetic makeup of such plasmids is vital for tracking and controlling antibiotic resistance spread.

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