ABSTRACT

In ectothermic fish, tuberculosis is a systemic, inflammatory disease typically caused by Mycobacterium marinum and characterized by granulomas in the internal organs. In homeothermic man, the same bacterium generally affects only the extremities. This is thought to be because, in culture, Mycobacterium marinum, grows well in cool temperatures and poorly in warm temperatures. However, Mycobacterium marinum has also been shown to cause debilitating systemic infections in other homeotherms. Here it is reported that Mycobacterium marinum infected a collection of ectothermic Egyptian spiny-tailed lizards, Uromastyx aegyptius, and did so peripherally. These animals were at one time housed in a large, dry, but unsterilized tank previously used for fish. As chronicled here, for nearly a year, members of the collection progressively suffered debilitating disease. Individuals were treated symptomatically, but, in the absence of specific indicators, treatment and diagnosis were difficult. Necropsies of affected animals showed infection by Mycobacterium marinum. This finding indicates that such bacilli can infect ectotherms other than fish, and that the infection can be confined to the extremities. Histopathology of biopsy specimens is necessary to diagnose this condition. Treatment was found to be unrewarding.