Biology Reference
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is shown in Figure 1. Both
P. gingivalis
and
F. nucleatum
formed discrete accumula-
tions and could be either separate from each other or interdigitated, consistent with the
concept that the later gram-negative colonizers such as
P. gingivalis
and
F. nucleatum
initially establish themselves on the streptococcal rich supragingival plaque [4, 18].
The results demonstrate the mutual compatibility of these three organisms for hetero-
typic community development, an early step in the overall process of plaque biofilm
accumulation. Participation in multi-species communities may provide a basis for syn-
ergistic interactions in virulence. For example, mixed infections of
P. gingivalis
and
F.
nucleatum
are more pathogenic in animal models than either species alone [22], and
F.
nucleatum
can enhance the ability of
P. gingivalis
to invade host cells [23].
Figure 1.
Confocal laser scanning microscopy of
P. gingivalis-F. nucleatum-S. gordonii
community.
The
S. gordonii
cells (red, stained with hexidium iodide) were cultured on a glass plate. The FITC-
labeled
F. nucleatum
cells (green), followed by DAPI labeled
P. gingivalis
cells (blue), were reacted
sequentially with the
S. gordonii
substratum. Bacterial accumulations were examined on a Bio-Rad
Radiance 2,100 confocal laser scanning microscope. A series of fluorescent optical x-y sections in
the z-plane to the maximum vertical extent of the accumulation were collected with Laser Sharp
software. Images were digitally reconstructed with Imaris software. Image is representative of three
independent experiments.
