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Plasmid pAMS1-encoded, bacteriocin-related "Siblicide" in Enterococcus faecalis

Christine M Sedgley1, Don B Clewell, Susan E Flannagan

  • 1Department of Cariology, Restorative Sciences & Endodontics, School of Dentistry, The University of Michigan, 1011 N. University Ave., Ann Arbor, MI 48109-1078, USA. csedgley@umich.edu

Journal of Bacteriology
|March 10, 2009
PubMed

Insights

Enterococcus faecalis bacteriocin MC4-1 shows sibling-killing activity. This activity is inhibited if the host bacteria also produce gelatinase, impacting bacteriocin detection.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacteriocin Research

Background:

  • Enterococcus faecalis is an opportunistic pathogen.
  • Bacteriocins are antimicrobial peptides with specific activity.
  • Plasmid pAMS1 carries genes for antibiotic resistance and bacteriocin production.

Purpose of the Study:

  • To investigate the "siblicidal" activity of the class IIa bacteriocin MC4-1.
  • To determine the influence of host factors on bacteriocin activity.

Main Methods:

  • Bacterial stab assays on solid medium.
  • Culturing of Enterococcus faecalis strains with and without plasmid pAMS1.
  • Observing zones of inhibition.

Main Results:

  • Plasmid-containing Enterococcus faecalis strains exhibited zones of inhibition, indicating sibling-killing activity.
  • The presence of gelatinase in the plasmid-containing host prevented bacteriocin detection.
  • Bacteriocin activity was conditional on the absence of host-produced gelatinase.

Conclusions:

  • The class IIa bacteriocin MC4-1 possesses conditional siblicidal activity.
  • Host-produced gelatinase interferes with the detection or activity of bacteriocin MC4-1.
  • This finding has implications for understanding bacteriocin function and plasmid biology in Enterococcus faecalis.

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