Classification of Mycobacterium avium and related opportunist mycobacteria met in England and Wales

Abstract

A broad division of the opportunist mycobacteria has been defined under the name of ‘dysgonic nonchromogens’. The classification was attempted of 68 strains isolated from man in England and Wales, of which 54 at least appeared to be clinically significant. The means used were chiefly drug sensitivity, arylsulphatase activity, specific agglutination, lipid analysis and pathogenicity tests on fowls. On the results, a new definition is proposed for the species M. avium, extending beyond the boundaries of pathogenicity for birds, and a scheme put forward for its division into two types. In addition, two provisional new species and a group of ‘para-avian’ bacilli have been recognized and defined. The remaining 16 strains included six with ‘Battey’ serotypes but otherwise could not be classified. The need for standardization of fowl tests has been noted together with their diminished importance in the field of classification with the emergence of new in vitro methods of examination.