Researchers uncover the spatial organization of bacterial communities associated with human tooth decay. The bacterium Streptococcus mutans is thought to be a key contributor to acid production and enamel dissolution in human tooth decay, or dental caries. The distribution of this bacterium appears to be localized to the site of caries, but the spatial organization of S. mutans and other oral bacteria in the disease is unknown. Marvin Whiteley, Hyun (Michel) Koo, and colleagues imaged intact biofilm colonies from 30 teeth of toddlers, 36-72 months of age, affected by caries. The authors identified a rotund organization of concentric layers of different bacteria in a corona-like structure. The pathogen S. mutans sits in the center of the structure, with layers of other streptococci as well as other bacteria surrounding the core. The layers, facilitated by an extracellular scaffold produced by S. mutans, protect the bacteria from antimicrobials and increase acid tolerance. The structure creates an acidic microenvironment at the biofilm-tooth interface, which causes dissolution of enamel and the onset of caries. According to the authors, examining micron-scale structures and the spatial organization of microbial communities in human-derived samples are key to understanding virulence and host-pathogen interactions in human tooth decay.
Article #19-19099: "Spatial mapping of polymicrobial communities reveals a precise biogeography associated with human dental caries," by Dongyeop Kim et al.
MEDIA CONTACT: Marvin Whiteley, Georgia Institute of Technology, Atlanta, GA; e-mail: marvin.whiteley@biosci.gatech.edu; Hyun (Michel) Koo, University of Pennsylvania, Philadelphia, PA; e-mail: koohy@upenn.edu
Images, along with caption and credit information, can be found at: https://drive.google.com/open?id=1bFzgRvbRxPZo5Qod-AzAX2jxnsNxMjrg
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Journal
Proceedings of the National Academy of Sciences