The effect of body temperature and cell-mediated immunity on the growth of Mycobacterium marinum and Mycobacterium leprae in mice

Department of Medical Microbiology, St George's Hospital Medical School, Cranmer Terrace, London, SW17 0RE Received March 4, 1981 Accepted April 2, 1981 SUMMARY. Evidence is presented that the high susceptibility of armadillos to infection with Mycobacterium leprae cannot be explained solely in terms of body temperature because mutant mice maintained with a body temperature similar to that of armadillos do not become heavily infected with M. leprae . The depression of cell-mediated immunity accompanying the low body temperature is not sufficient to produce an overwhelming infection. The results obtained with M. marinum suggest that whereas lack of cell-mediated immunity or a low body temperature result in a moderately enhanced infection in the mouse a combination of both of these factors is required to produce an overwhelming infection involving the internal organs. * Present address: Department of Botany, University of Bristol.