FIG 4 .

Micrographs of acridine orange-stained microbial communities occurring in the natural estuarine aquatic ecosystem of the mangrove forest, Sundarbans, Bay of Bengal, Bangladesh, where cholera is endemic. The micrographs provide in situ evidence of free-living bacteria in a natural aquatic ecosystem assembling and transforming into smaller and coccoid cells in the spring and fall (B and D) and forming biofilm consortia during the winter and monsoon months of the year (A and C). Scale bars in red indicate 10 µm.