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Genetic transformation in some cariogenic Streptococcus milleri.
A E Jacob1, W A Horton, D B Drucker
1Department of Biochemistry and Molecular Biology, University of Manchester, Great Britain.
Microbios
|January 1, 1989
Summary
A cariogenic Streptococcus milleri strain, CR 287, demonstrated spontaneous transformability and rapid DNA uptake. Its competence factor (CF) induced competence in other strains, suggesting diverse CF types in S. milleri.
Area of Science:
- Microbiology
- Genetics
- Oral Health Research
Background:
- Streptococcus milleri is implicated in dental caries.
- Spontaneous transformability varies among S. milleri strains.
- Competence factor (CF) regulates genetic transformation in bacteria.
Purpose of the Study:
- To investigate the transformability of Streptococcus milleri strains.
- To characterize DNA uptake and competence factor production in S. milleri.
- To explore the potential for genetic manipulation of cariogenic S. milleri strains.
Main Methods:
- Assessing spontaneous transformation frequency in S. milleri strains.
- Measuring DNA uptake rates in relation to cellular competence.
- Evaluating the ability of competence factors to induce competence in other strains.
- Transforming strains using plasmid shuttle cloning vector pVA838 DNA.
Main Results:
- Only one of six S. milleri strains (CR 287) was spontaneously transformable.
- Strain CR 287 exhibited rapid DNA uptake at optimal competence (15 min).
- CR 287's CF induced high competence in a non-transformable cariogenic strain (NCTC 11169), unlike NCTC 10707's CF.
- Three S. milleri strains were transformable with pVA838.
Conclusions:
- S. milleri possesses diverse competence factor (CF) types, similar to S. sanguis.
- The CF of strain CR 287 plays a crucial role in inducing competence in other S. milleri strains.
- Understanding S. milleri transformability is key for developing novel strategies against dental caries.