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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
Summary
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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