Oral Site Specific Sampling Reveals Differential Location for Scardovia wiggsiae

Introduction: The newly discovered cariogenic pathogen Scardovia wiggsiae has been the subject of intense scientific interest due to the role it may play in the development or progression of caries and oral disease. The primary objective of this study was to perform DNA microbial screening from five specific oral sites, including the gingival crevice between the upper central incisors, biofilm of the upper first molar and lingual incisor, as well as the dorsum of the tongue – for comparison with unstimulated saliva. These data may provide significant insights into site-specific oral locations that harbor S. wiggsiae.

Methods: More than one hundred previously collected clinical samples (n=105) were identified for inclusion in this study. DNA isolates were screened using a NanoDrop spectrophotometer to determine overall DNA quantity and quality. Samples with sufficient quality and quantity were screened for the presence of S. wiggsiae using validated PCR primers.

Results: More than one hundred patient samples (n=105) were identified, which were comprised of mostly female (57%) versus male (43%) and minority (71%) versus White (29%). The average DNA concentrations ranged between 13.74 and 14.69 mg/mL, with A260:A280 ratios ranging between 1.62 – 1.70. Results of molecular screening using S. wiggsiae specific primers demonstrated only a small percentage of pooled samples (7.6%) harbored this DNA, which was highly concentrated among the samples from tooth surfaces (Upper First Molar, Lingual Incisor) and saliva compared with the gingival crevice and dorsum of the tongue.

Discussion: These data provide novel information regarding specific oral locations, including tooth surfaces that harbor S. wiggsiae. In addition, these sites also provide new information regarding oral sites that do not appear to harbor this organism, including the gingival crevice and dorsum of the tongue. This information may be particularly useful to oral health researchers as they strive to limit and reduce the cariogenic microbiome among high-risk populations.