10.6084/m9.figshare.5716150.v1
Huang X.
Huang
X.
Browngardt C.M.
Browngardt
C.M.
Jiang M.
Jiang
M.
Ahn S.-J.
Ahn
S.-J.
Burne R.A.
Burne
R.A.
Nascimento M.M.
Nascimento
M.M.
Supplementary Material for: Diversity in Antagonistic Interactions between Commensal Oral Streptococci and Streptococcus mutans
Karger Publishers
2017
Antagonism
Arginine
Bacteria
Biofilm
Dental caries
2017-12-19 15:35:03
Journal contribution
https://karger.figshare.com/articles/journal_contribution/Supplementary_Material_for_Diversity_in_Antagonistic_Interactions_between_Commensal_Oral_Streptococci_and_Streptococcus_mutans/5716150
<p>Arginine metabolism via the arginine deiminase system (ADS) of oral
bacteria generates ammonia, which can increase the pH of oral biofilms
and decrease the risk for dental caries. Antagonistic interactions
between ADS-positive and cariogenic bacteria in oral biofilms may be an
important ecological determinant of caries. This study investigated the
antagonistic potential and mechanisms of clinical isolates of
arginolytic streptococci on and by <i>Streptococcus mutans </i>UA159, a well-characterized cariogenic human isolate. Low-passage isolates of <i>Streptococcus gordonii</i>, <i>Streptococcus sanguinis</i>, <i>Streptococcus parasanguinis, Streptococcus australis</i>, and <i>Streptococcus cristatus</i> inhibited the growth of <i>S. mutans </i>to various degrees when they were inoculated on growth media first or simultaneously with <i>S. mutans</i>. The antagonistic effects of arginolytic strains against <i>S. mutans </i>and the production of H<sub>2</sub>O<sub>2</sub>
by these strains were enhanced during growth in a less-rich medium or
when galactose was substituted for glucose as the primary carbohydrate
source. Pyruvate oxidase was the dominant pathway for H<sub>2</sub>O<sub>2</sub> production by arginolytic strains, but lactate oxidase activity was also detected in some strains of <i>S. gordonii</i> and<i> S. cristatus. </i>UA159
inhibited the growth of all tested arginolytic strains when inoculated
first, especially in aerobic conditions. However, the antagonistic
effects of <i>S. mutans </i>on certain strains of <i>S. gordonii</i> and<i> S. australis</i>
were not observed during anaerobic growth in the presence of arginine.
Thus, arginolytic commensal streptococci may have a synergistically
positive impact on the ecology of oral biofilms by moderating biofilm pH
while antagonizing the growth and virulence of caries pathogens.</p>