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Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
Published on: May 2, 2018
Bacterial plasmids: replication of extrachromosomal genetic elements encoding resistance to antimicrobial compounds
L A Actis1, M E Tolmasky, J H Crosa
1Department of Microbiology, Miami University, Oxford, Ohio 45056-8900, USA. actisla@muohio.edu
Frontiers in Bioscience : a Journal and Virtual Library
|January 5, 1999
Summary
Plasmids are extrachromosomal DNA that help bacteria survive environmental challenges and compete. These genetic elements, crucial in medicine for antibiotic resistance and virulence, rely on host factors for replication.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Plasmids are self-replicating, extrachromosomal DNA molecules present in various microorganisms, including bacteria and fungi.
- While typically circular and double-stranded, linear plasmids have also been identified.
- Plasmids are not essential for bacterial survival but confer adaptive advantages, such as enhanced environmental resilience and competitive edge.
Purpose of the Study:
- To elucidate the fundamental characteristics and biological significance of plasmids.
- To highlight the medical importance of plasmids, particularly those conferring antibiotic resistance and virulence traits.
- To explore the mechanisms of plasmid replication and the factors influencing plasmid properties.
Main Methods:
- Review of existing literature on plasmid biology.
- Analysis of genetic determinants encoded by plasmids.
- Examination of plasmid replication mechanisms (rolling circle and theta).
Main Results:
- Plasmids encode genetic determinants that enhance host survival and competitiveness.
- Medical significance is evident through plasmid-mediated antibiotic resistance and virulence.
- Replication initiation occurs at a specific site (ori) and relies on host factors.
- Plasmid replication can follow rolling circle or theta mechanisms.
- Plasmid-encoded elements regulate copy number and incompatibility.
Conclusions:
- Plasmids are vital genetic elements with significant roles in bacterial adaptation and evolution.
- Their role in antibiotic resistance and virulence underscores their medical importance.
- Understanding plasmid replication mechanisms is key to understanding their biology and potential applications.
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