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Transfection of Streptococcus sanguis by phage deoxyribonucleic acid isolated from Streptococcus mutans
Abstract:
Streptococcus sanguis ATCC 10556 cells were infected with free phage DNA of S, mutans strain PK 1. Two transformants were isolated which made colonies with large mucoid forms on mitis-salivarius agar. Both transformants had an increased ability to synthesize insoluble glucan and showed an adhesive nature on glass surfaces. These characteristics of the transformants bear a resemblance to S. mutans. These transformants had many physiological characteristics by which they could be recognized as S. sanguis. However, they resembled S. salivarius in forming a large amount of soluble fructan. Furthermore, the transformant cells did not produce ammonia from arginine, whereas their parent cells did.
Insights
Researchers transformed Streptococcus sanguis with Streptococcus mutans phage DNA, creating hybrid cells. These transformants exhibited characteristics of both parent species, including enhanced glucan synthesis and altered fructan production.
Area of Science:
- Microbiology
- Molecular Biology
- Bacteriology
Background:
- Streptococcus sanguis and Streptococcus mutans are oral bacteria implicated in dental plaque formation.
- Genetic manipulation of oral streptococci can alter their virulence factors and cariogenic potential.
- Understanding interspecies gene transfer is crucial for controlling oral biofilm development.
Purpose of the Study:
- To investigate the genetic transfer of traits between Streptococcus sanguis and Streptococcus mutans.
- To characterize the physiological and biochemical properties of resulting transformant strains.
Main Methods:
- Infection of Streptococcus sanguis ATCC 10556 with free phage DNA from Streptococcus mutans strain PK 1.
- Isolation and characterization of transformant colonies on mitis-salivarius agar.
- Assessment of insoluble glucan synthesis, cell adhesion to glass, soluble fructan production, and ammonia production from arginine.
Main Results:
- Two transformants were successfully isolated, displaying mucoid colony morphology.
- Transformants showed increased insoluble glucan synthesis and enhanced adhesion to glass, resembling Streptococcus mutans.
- Transformants produced significant amounts of soluble fructan, similar to Streptococcus salivarius, and lost the ability to produce ammonia from arginine.
Conclusions:
- Genetic transformation between Streptococcus sanguis and Streptococcus mutans can result in hybrid strains with mixed phenotypic characteristics.
- These findings highlight the potential for horizontal gene transfer to influence the virulence and ecological niche of oral bacteria.
- The altered metabolic profiles of transformants suggest complex genetic interactions and potential implications for dental caries research.