FIG. 1.

Colony morphology and capsule production studied by SEM and TEM. Bacteria isolated from great apes (A, C, E, and G) and classic B. anthracis strains (B, D, F, and H) presented the same morphological criteria. The same colony morphology on agar was seen by SEM (A to D). Cells from suspension cultures showed the same capsule and filament (piles) morphology by negative staining (E and F), and a capsule fringe at the outer wall of the bacteria in thin cross-sections by TEM (G and H). Similar results were obtained with all bacterial isolates tested.