Acanthamoeba castellani is a free living amoebae found in soil and water and can be an opportunistic pathogen as well. They have been diagnosed as the causative agent associated with keratitis, an infection of the eye, in humans. Other opportunistic pathogens are Naegleria and Balamuthia which have been associated with amebic encephalitis. Acanthamoeba and Naegleria feed by phagocytosis while Balamuthia feed by inserting the tips of their pseudopodia into cells. The other members of the video group, Naegleria and Balamuthia, are linked to this movie. The cells were grown in axenic media. Then they were photographed with a Canon Power Shot G3 with a setting at ISO 50 with an optical microlens at 4X and the quality set at RAW. The camera was attached to the phototube of the microscope with a 3X lens and photographed in phase contrast with a 100X oil immersion objective. Live amoebae were placed in a chamber prepared by inverting a coverslip with/or without cultured mammalian cells onto a 3X1 inch microscope slide with a thin rim of Vaseline; melted paraffin was brushed around the edge of the coverslip to seal it to the slide. Such cultures could be maintained for several days at room temperature.
Biological Process: Pseudopodium organization, Pseudopodium assembly, Pseudopodium retraction
Author: Thelma Dunnebacke
Source: The Cell: An Image Library
