Related Experiment Video

Updated: May 7, 2026

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
06:56

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli

Published on: March 24, 2023

Interference in pheromone-responsive conjugation of a high-level bacitracin resistant Enterococcus faecalis plasmid

Cindy-Love Tremblay1, Marie Archambault

  • 1GREMIP research group, Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte Street, Saint-Hyacinthe, QC J2S 7C6, Canada. cl.tremblay@umontreal.ca

International Journal of Environmental Research and Public Health
|September 14, 2013
PubMed

Insights

Researchers disrupted antimicrobial resistance gene transfer in Enterococcus faecalis using antibodies against aggregation substance (AS). This interference significantly reduced the spread of bacitracin resistance (bcr) genes, offering insights into controlling antibiotic resistance.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Enterococcus faecalis, a bacterium of poultry origin, can transfer antimicrobial resistance genes through conjugation.
  • Pheromone-responsive conjugation in E. faecalis facilitates the horizontal transfer of antibiotic resistance genes, posing clinical challenges.
  • Aggregation substance (AS) plays a role in the cell-to-cell contact required for efficient conjugative transfer.

Purpose of the Study:

  • To investigate the role of aggregation substance (AS) in the pheromone-responsive conjugation of a bacitracin-resistant Enterococcus faecalis plasmid.
  • To evaluate the potential of using polyclonal antiserum against AS to interfere with antimicrobial resistance gene transfer.

Main Methods:

  • Conjugative transfer experiments were performed using donor E. faecalis strain 543 and recipient E. faecalis JH2-2, with and without pheromone induction.
  • Polyclonal antiserum against AS (anti-AS(44-560)) was used to assess its interference with conjugation.
  • Genes asa1, bcrRAB, and traB were confirmed in transconjugants using antimicrobial susceptibility testing, PCR, Southern hybridization, and sequencing.

Main Results:

  • Pheromone induction of E. faecalis strain 543 led to clumping and high transfer frequencies of bacitracin resistance (bcr) genes.
  • Addition of anti-AS(44-560) significantly reduced aggregate formation and interfered with pheromone-responsive conjugation.
  • Horizontal transfer of asa1 and bcr genes was significantly reduced in the presence of anti-AS antibodies.

Conclusions:

  • Aggregation substance (AS) is crucial for the efficient pheromone-responsive conjugation and horizontal transfer of antimicrobial resistance genes in E. faecalis.
  • Targeting AS with specific antibodies can effectively reduce the spread of antibiotic resistance, offering a potential strategy for clinical intervention.
  • Understanding and disrupting conjugation mechanisms are vital for combating the growing threat of antimicrobial resistance.

More Related Videos

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation10:41

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Published on: January 4, 2017

High-Resolution Comparison of Bacterial Conjugation Frequencies05:18

High-Resolution Comparison of Bacterial Conjugation Frequencies

Published on: January 10, 2019

Related Concept Videos

Mechanism of Conjugation01:19

Mechanism of Conjugation

Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
Conjugation01:19

Conjugation

Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Antibiotic Selection00:57

Antibiotic Selection

Overview