Genotyping and Phenotypic Analysis of Streptococcus mutans Isolates From Children With and Without Dental Caries
Year: 2018
Type: dissertation
Abstract: Within dental plaque, Streptococcus mutans produces acids from fermentable carbohydrates, decreasing the biofilm pH, causing enamel demineralization. S. mutans produces persisters, dormant variants of cells that survive lethal antibiotic concentrations without developing antibiotic resistance. Persisters have been associated with infection chronicity. We hypothesized that phenotypic heterogeneity of S. mutans is directly associated with cariogenicity. S. mutans were isolated from plaque collected from caries-free (CF) children and children with Severe Early Childhood Caries (S-ECC). For each identified genotype, an acid tolerance analysis was performed and persisters were quantified. In S-ECC patients with >1 strain, the dominant strain exhibited higher cell survival following exposure to pH 3.2, whereas in CF patients, survival was similar. S. mutans isolates from S-ECC patients produced ~15x more persisters than isolates from CF patients. S. mutans exhibits phenotypic diversity. The ability of S. mutans to produce high levels of persisters may be a hallmark of cariogenicity.
Source: TSpace (University of Toronto)
Author: Aaron Bottner
Language: English
Subfield: Periodontics
Field: Dentistry
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2920794494