Figure 5.

Hedgehog-shape structure. (A–D,F–H) represents a single focal plane nearby the middle part of the structure. (A) Corynebacterium sp. filaments radiating outward from near the center of the image and coccoid Streptococcus sp. cells arranged around the distal tips of the Corynebacterium sp. filaments. (B) Cells of Haemophilus/Aggregatibacter sp. and Porphyromonas sp. sited at the structure’s periphery, in the same region as the Streptococcus sp. cells. Capnocytophaga sp. also inhabited a wideband inside the periphery. (C) Fusobacterium sp. and Leptotrichia sp. occupying this band called “filament-rich halo”. Neisseriaceae establishing constellations in and nearby the periphery. Actinomyces sp. represented by a small number of cells located near the structure’s base. (D) All taxa overlayed. Many cells from the “filament-rich annulus” overlapped the exterior of the consortia. (E–G) Detail of the Corynebacterium’s arrangement relatively to other taxa. (E) The maximum intensity projection of three adjacent optical sections shows that these filaments are continuous from the center to the periphery of the structure for more than 50 µm. Some filaments persist visible within the Streptococcus sp. cells. (F) Detail of the periphery. Corncob structures are composed of a filamentous core (sometimes visualized as Corynebacterium filaments but often not stained) bordered primarily by Streptococcus sp. cells but also by Porphyromonas sp. and Haemophilus/Aggregatibacter sp., both in proximal contact with Streptococcus sp. cells. (G) On the periphery of these corncob structures, Corynebacterium sp. filaments pass through the halo that is highly densely colonized with elongated rods of Fusobacterium sp., Leptotrichia sp., and Capnocytophaga species. (H) The fluorescent signal of the universal probe EUB338. (I–L) The exterior of the hedgehog structure, composed mainly of corncobs. (K) The edge of the Fusobacterium-Leptotrichia sp. halo. Reprinted with the publisher’s permission.