Rev. sci. tech. Off. int. Epiz., 2001,20 (1), 265-290 Mycobacterial infections in domestic and wild animals due to Mycobacterium marinum, M. fortuitum, M. chelonae, M. porcinum, M. farcinogenes, M. smegmatis, M. scrofulaceum, M. xenopi, M. kansasii, M. simiae and M. genavense H. Bercovier (1) & V. Vincent (2) (1) Institute of Microbiology, Faculty of Medicine, The Hebrew University of Jerusalem, Ein Karem, Jerusalem 91010, Israel (2) Laboratoire de Référence des Mycobactéries, Centre National de Référence des Mycobactéries, Institut Pasteur, 25-28 rue du Docteur-Roux, 75724 Paris Cedex 15, France Summary The epidemiology and the natural distribution of Mycobacterium marinum, M. fortuitum, M. chelonae, M. porcinum, M. farcinogenes, M. smegmatis, M. scrofulaceum, M. xenopi, M. kansasii, M. simiae and M genavense are described. In addition to the bacteriological, biochemical and genetic characteristics, the authors review the pathology of these species, including the natural and experimental diseases and the accompanying lesions, diagnosis, antibiotic sensitivities and treatment of animal infections caused by these mycobacteria. Keywords Antibiotics - Diagnosis - Domestic animals - Epidemiology - Mycobacteria - Pathology— granulomatous disease associated with lymphadenopathy, although acute disease can also be a feature. The intracellular localisation of these pathogens is reflected well in the pathology of these pathogens. Mycobacterium marinum, M. fortuitumand M. chelonaeare the only described NTM pathogens of fish, although the organisms can also be found in other animal species, In contrast, M, xenopi for which water is the proven reservoir, has not yet been implicated in diseases of fish, despite descriptions of infection by this mycobacterium in toads. Mycobacterium scrofulaceum, M. xenopi, M. kansasii, M. simiae and M. porcinumare mainly isolated from lymph nodes of animals post mortem.The role of M. farcinogenesin bovine farcy still requires clarification. Finally, infections due to M. genavense in birds can be considered as a new emerging disease caused by a newly discovered agent. Wild animals. Introduction The 'atypical' or non-tuberculous mycobacteria (NTM) are mycobacteria belonging to species other than those classified in the Mycobacterium tuberculosiscomplex (M. tuberculosis, M. bovis, M. africanum, M. microti and the newly described M. canetti). These mycobacteria have been long recognised as potential pathogens for animals and humans. Some species are opportunistic pathogens for animals (M, scrofulaceum), some are primary pathogens for animals (M, genavensefor birds) and some are agents of zoonosis (M, marinum),The importance of NTM in human pathology has dramatically increased due to the epidemic of acquired itnmune deficiency syndrome(AIDS),These mycobacteria are frequent pathogens of patients with underlying immunodeficiency. The pathology resulting from infections due to these mycobacteriais most often expressed as a chronic