Aspects of the epidemiology of bovine tuberculosis in badgers and cattle. II. The development and use of a typing system for Mycobacterium bovis.

A relatively simple method for the detection of intra-specific variation of Mycobacterium bovis is described, based on the ability of strains to utilize or remove amino acids from solution. Using the method, 31 strains of M. bovis, isolated badgers and cattle, have been divided in to four major groups with some additional sub-groups and intermediate strains. Preliminary results suggest that the biotypes observed are relatively stable. The method was used in the investigation of an outbreak of bovine tuberculosis in cattle in Gloucestershire where badgers were implicated as a source of infection. The results suggested that transmission of infection had occurred on at least two or three separate occasions. It is suggested that the method could be used in studying the epidemiology of bovine tuberculosis in wild animals, cattle and man.