ABSTRACT
BACKGROUND: The oral microbiome is a complex assembly of microbial species, whose constituents can tilt the balance towards progression of oral disease or sustained health. Recently we identified sex-specific differences in the salivary microbiome contained within caries-active and caries-free children. In this study, we sought to ascertain if adjunctive dental therapies, including povidone iodine and chlorhexidine, were effective in shifting the cariogenic microbiome from dysbiosis to non-cariogenic health. DESIGN: We recruited young children (ages 2-12 years) to enter five enrollment groups, with each group (N = 9-30 participants/group) receiving caries restorative and/or adjunctive therapies, either singularly or in combination (OHSU IRB #6535). Saliva specimens were collected pre- and post-treatment (4-8 weeks) of caries preventive measures, and oral microbiota were identified using next generation sequencing (HOMINGS, Forsyth Institute, Cambridge, MA). RESULTS: With the use of multi-dimensional scaling plots, support vector machine learning, odds ratio analysis, and other statistical methods, we have determined that treatment with povidone iodine can shift the composition of the salivary cariogenic microbiome to include higher proportions of aerobic microorganisms, such as Stentrophomonas maltophila, as well as non-cariogenic, anaerobic microorganisms including Poryphyromonas and Fusobacterium species. CONCLUSION: We have identified microorganisms that are associated with caries-active children and have determined that povidone iodine is an effective adjunctive therapy that has the potential to shift the composition of the cariogenic microbiome to one more closely aligned with non-cariogenic health.
ABSTRACT
BACKGROUND AND OBJECTIVES: Acute apical abscesses are serious endodontic diseases resulting from pulpal infection with opportunistic oral microorganisms. The objective of this study was to identify and compare the oral microbiota in patients (N=18) exhibiting acute apical abscesses, originating from the demographic region in Portland, Oregon. The study hypothesis is that abscesses obtained from this demographic region may contain unique microorganisms not identified in specimens from other regions. DESIGN: Endodontic abscesses were sampled from patients at the Oregon Health & Science University (OHSU) School of Dentistry. DNA from abscess specimens was subjected to polymerase chain reaction amplification using 16S rRNA gene-specific primers and Cy3-dCTP labeling. Labeled DNA was then applied to microbial microarrays (280 species) generated by the Human Oral Microbial Identification Microarray Laboratory (Forsyth Institute, Cambridge, MA). RESULTS: The most prevalent microorganisms, found across multiple abscess specimens, include Fusobacterium nucleatum, Parvimonas micra, Megasphaera species clone CS025, Prevotella multisaccharivorax, Atopobium rimae, and Porphyromonas endodontalis. The most abundant microorganisms, found in highest numbers within individual abscesses, include F. nucleatum, P. micra, Streptococcus Cluster III, Solobacterium moorei, Streptococcus constellatus, and Porphyromonas endodontalis. Strong bacterial associations were identified between Prevotella multisaccharivorax, Acidaminococcaceae species clone DM071, Megasphaera species clone CS025, Actinomyces species clone EP053, and Streptococcus cristatus (all with Spearman coefficients >0.9). CONCLUSIONS: Cultivable and uncultivable bacterial species have been identified in endodontic abscesses obtained from the Portland, Oregon demographic region, and taxa identifications correlated well with other published studies, with the exception of Treponema and Streptococcus cristae, which were not commonly identified in endodontic abscesses between the demographic region in Portland, Oregon and other regions.
