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A High-throughput-compatible FRET-based Platform for Identification and Characterization of Botulinum Neurotoxin Light Chain Modulators
Published on: December 27, 2013
Conjugative botulinum neurotoxin-encoding plasmids in Clostridium botulinum
Kristin M Marshall1, Marite Bradshaw, Eric A Johnson
1Department of Bacteriology, College of Agriculture and Life Sciences, University of Wisconsin, Madison, Wisconsin, USA.
Plos One
|June 17, 2010
Summary
This study demonstrates that Clostridium botulinum botulinum neurotoxin (BoNT)-encoding plasmids can be transferred between bacteria through conjugation. This finding reveals a mechanism for the spread of BoNT genes among C. botulinum strains.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Clostridium botulinum produces seven distinct botulinum neurotoxin (BoNT) serotypes.
- BoNT-encoding genes are located on plasmids in several C. botulinum strains, suggesting potential plasmid transfer.
- The conjugative ability of these BoNT-encoding plasmids remains largely uncharacterized.
Purpose of the Study:
- To investigate whether Clostridium botulinum botulinum neurotoxin (BoNT)-encoding plasmids are conjugative.
- To determine the mechanism of BoNT plasmid dissemination within C. botulinum populations.
Main Methods:
- BoNT-encoding plasmids from C. botulinum strains were tagged with an erythromycin resistance marker using ClosTron mutagenesis.
- Mating experiments were conducted between tagged plasmid donor strains and tetracycline-resistant recipient C. botulinum strains.
- Plasmid transfer was confirmed using pulsed-field gel electrophoresis (PFGE) and Southern hybridizations.
Main Results:
- Conjugal transfer of tagged botulinum neurotoxin (BoNT)-encoding plasmids was successfully demonstrated between C. botulinum strains.
- Transconjugants acquiring the resistance markers were isolated, confirming plasmid acquisition.
- Evidence indicated that plasmid transfer requires cell-to-cell contact and is DNase resistant, consistent with conjugation.
Conclusions:
- This study provides the first evidence for the conjugal transfer of native botulinum neurotoxin (BoNT)-encoding plasmids in Clostridium botulinum.
- Conjugation represents a likely mechanism for the lateral dissemination of BoNT-encoding plasmids among C. botulinum strains.
- The potential transfer of these plasmids to other bacterial hosts raises significant concerns for human pathogenicity and warrants further investigation.
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