Journal of Dental Research, Vol 69, 483-488, Copyright © 1990 by International & American Associations for Dental Research Online Journals
Colonization resistance of defined bacterial plaques to Streptococcus mutans implantation on teeth in a model mouth
C. J. Perrons and H. D. Donoghue
University College, London, England.
We investigated the ability of Streptococcus mutans C67-1 to colonize
simple bacterial plaques and the effects of age and stability of the
pre-formed plaque on colonization resistance. Mixed-plaques of Actinomyces
viscosus WVU627, 'Streptococcus mitior' LPA-1, and Veillonella dispar
OMZ193 were grown on tooth segments, mounted back to back for simulation of
approximal sites in a model mouth for 66 h. S. mutans C67-1 was either
included in the original inoculum or super-inoculated onto the developing
plaque. Inclusion of S. mutans C67-1 did not alter the total viable counts,
but the proportional composition changed due to inter-species interactions.
Colonization resistance of the mixed-plaque samples developed within 24 h,
although S. mutans C67-1 was always able to colonize these stagnation
sites. Colonization resistance of 24-hour plaque against a fresh isolate,
S. mutans CP3, was also studied. There was greater colonization resistance
by the basic plaque to this organism, compared with S. mutans C67-1,
although the reasons for this were not clear. These initial experiments
demonstrate the way in which the factors involved in bacterial colonization
resistance in microbial films on teeth can be studied under controlled
conditions.
