Fig. 1.

Micrographs showing V. cholerae O1 in MW microcosms at different stages of incubation at room temperature (RT) (MW-RT). Cells were collected from microcosms, and smears were prepared on clean glass slides, air-dried, stained with crystal violet, washed, and visualized by using a phase-contrast microscope (model BX2; Olympus, Tokyo, Japan). Cells at day 1 were observed to be arranged in microcolonies (A), with larger aggregations in dark blue, an indication of biofilm, at day 7 (B). Cells appeared as multiple layers, tightly attached to thick biofilm surrounding the aggregations of cells at day 27 (C) and as aggregates of thick biofilm intensifying with time at day 45 (D).