Abstract: | The effect of chloramphenicol (CAP) on the bacterial endosymbiotes of a strain of Amoeba proteus was studied by growing the symbiotic amebae in media containing 0.5-1.6 mg/ml CAP for up to 4 weeks. Treatments with CAP caused such ultrastructural changes as expansion of the nuclear zone and deformation of symbiotes. The CAP treatment also damaged the mitochondria, e.g. disappearance of central and protrusion of peripheral cristae. Number of bacteria per ameba decreased to less than 10% of control in CAP-containing media, but no viable amebae became completely free of symbiotes. The results supported previous studies that amebae were dependent on endosymbiotes. |