Serotaxonomical analyses of strains referred to Nocardia amarae and Rhodococcus equi.

Four strains of Nocardia amarae and four strains of Rhodococcus equi (earlier designated Corynebacterium equi) were analysed by means of the comparative immunodiffusion technique for taxonomical purposes. Nineteen reference precipitation systems, representing different species of Corynebacterium, Mycobacterium, Nocardia, Rhodococcus, Streptomyces, and related taxa were employed. The N. amarae strains differed serologically from the reference strains of Nocardia and their assignment to the latter genus was therefore questioned. Furthermore, the results provided additional evidence for the view that R. equi belongs to the genus Rhodococcus and not to the genus Corynebacterium.