Mycobacteriosis in Norwegian farmed Atlantic salmon (Salmo salar L.)

Abstract

Mycobacteriosis in fish is a group of serious, often lethal, systemic diseases affecting a wide range of species in fresh water, brackish water and sea water. The disease is caused by members of the genus Mycobacterium, which are Gram-positive, acid-fast rods. This genus is traditionally divided into two groups: the M. tuberculosis-complex which comprise the species that cause tuberculosis in mammals, and the non-tuberculous mycobacteria (Spickler & Dvorak, 2020).At least 20 species of non-tuberculous mycobacteria can cause disease in fish, but Mycobacterium marinum, M. chelonae, M. fortuitum, M. abscessus and M. salmoniphilum, all belonging to the 'M. chelonaecomplex', are perhaps the best-known species pathogenic to fish