Clostridium difficile colony

Clostridium difficile is a major cause of antibiotic-associated diarrheal disease. This false-coloured scanning electron micrograph shows part of the expanding edge of a bacterial colony in situ on an agar plate. Both vegetative cells and spores are visible. In order to study and accurately profile an intact colony it has been essential to minimise the disturbance of the cells. In this way it has been possible to optimise conditons for spore formation, characterise different cell morphologies across the colony and to study biofilm formation directly.