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Streptococcus mutans in a wild, sucrose-eating rat population
Infection and Immunity
|July 1, 1974
Summary
Streptococcus mutans, linked to dental caries, was found in wild rats consuming sugar cane. This suggests the bacteria
Area of Science:
- Microbiology
- Oral Health
- Zoology
Background:
- Streptococcus mutans is a primary cause of dental caries.
- Previously, S. mutans was only found in humans and specific laboratory animals.
Purpose of the Study:
- To investigate the presence and characteristics of Streptococcus mutans in wild rat populations.
- To determine the genetic relatedness of S. mutans strains isolated from rats to known human and animal strains.
Main Methods:
- Isolation and culturing of bacteria from wild rat mouths.
- Biochemical characterization of isolated strains (fermentation, salt tolerance, temperature tolerance).
- In vitro plaque formation assays.
- Intracellular polysaccharide storage analysis.
- Deoxyribonucleic acid-deoxyribonucleic acid reassociation for genetic typing.
Main Results:
- S. mutans was successfully isolated from wild rats that consumed sugar cane.
- Isolated strains exhibited characteristics consistent with S. mutans, including mannitol/sorbitol fermentation and in vitro plaque formation.
- Two distinct genetic types of S. mutans were identified in the rat population.
- One genetic type was closely related to human/hamster S. mutans strains, while the other appeared novel.
Conclusions:
- The ecological association of teeth, sucrose, and S. mutans is not exclusive to humans and laboratory animals.
- Wild rat populations can serve as a reservoir for S. mutans, expanding its known ecological niche.
- Discovery of novel genetic types highlights the adaptability and diversity of S. mutans.