Amino Sugars Modify the Ability of Beneficial Commensal Oral Bacteria to Antagonize Streptococcus mutans

Daria Muklewicz

Authors:  Daria M. Muklewicz, Robert A. Burne and Lin Zeng

Faculty Mentor:  Robert Burne

College:  College of Dentistry


Streptococcus mutans, a primary etiologic agent of dental caries, is adept at driving the formation of pathogenic biofilms. Certain oral commensal streptococci can potently antagonize S. mutans, but the effects are dependent on environmental factors. Using a known pathogenic strain of S. mutans (UA159) tagged with a green fluorescent protein and an antibiotic resistance marker, we examined the abilities of 50 low-passage commensal oral Streptococcus strains to compete in a two-species biofilm model with S. mutans when growing on the amino sugar N-acetylglucosamine (GlcNAc), compared to the same set of strains growing on glucose. Growth on GlcNAc substantially improved the competitive fitness of the commensals. A subset of commensal strains was selected and the effects of GlcNAc on the ability of the commensals to protect an oral Streptococcus species from killing by S. mutans were examined using a deferred antagonism assay. Collectively, the results demonstrate that GlcNAc can enhance the probiotic properties of beneficial health-associated commensals. This research establishes a foundation for designing novel therapeutic approaches that incorporate amino sugars to moderate the pathogenic potential of oral biofilms, thus decreasing the tremendous burden of dental caries and other oral infectious diseases.

Poster Pitch

Click the video below to view the student's poster pitch.


Click the image to enlarge.
6 Responses
  1. Nirali Pathak

    Hi Daria!! You did some very interesting work with amino sugars and oral bacteria! Interested to see what will be done with the results from your study. Keep up the great work!

    1. Daria Muklewicz

      Hi Nirali! Thank you very much. I hope that you learned something new about how cavities work!