The mycobacteria

The mycobacteria belong to the Corynebacterineae subclass of the actmobacteria and are remarkable manly for then ability to cause disease in animals. They can be divided into two groups based on their growth characterisucs. The fast-growing mycobacteria include non-pathogens such as the model organism Mycobacterium smegmatis, and opportunistie pathogens such as Mycobacterium chelonei, which can cause septicaemia. The slow-growing mycobacteria include all the nasty animal pathogens such as Mycobacterium leprae and Mycobacterium tuberculosis. The slow-growing mycobacteria also include Mycobacterium marinum, which has potential as a model organism for studying mycobacterial infections. It causes tuberculosis-like granulomas in fish and amphibians and can also cause skin infections in humans. Human infection, often referred to as 'swimming pool granuloma', is rare and is thought to occur when water containing M. marinum was recently completed by the Sanger Centre in Cambridge and shares very high identity with that of M. tuberculosis. Since it can be grown under containment level II facilities it can be used to study virulence genes in mycoacteria, using fish or amphibians as animal models.