Comparative metabolism of species and types of organisms within the genus Brucella.

The classification of organisms in the genus Brucella recognizes three species. Huddleson (1957) expanded this classification by subgrouping the species into types in order to accommodate taxonomically the increased number of organisms reported to be atypical of a species (Wilson, 1933; Renoux and Carrere, 1952; Renoux, 1952a, b; Cruickshank, 1954; Huddleson and White, 1954; Pickett et al., 1953; Pickett and Nelson, 1955). Meyer and Cameron (1957, 1958) reported that typical organisms of each of the three species displayed distinctive and characteristic metabolic patterns under manometric conditions on substrates of amino acids and carbohydrates. Gram-negative microorganisms that are morphologically similar to brucellae, one of which is tentatively classified within this genus (Buddle and Boyes, 1953), could be differentiated from brucellae by its oxidative metabolism (Meyer and Cameron, 1956). Organisms that have been classified within the genus, but which are atypical of the existing species (Stoenner and Lackman, 1957), can also be identified by this method (Cameron and Meyer, 1958). It was therefore considered highly desirable to extend these investigations to include all atypical organisms (types) within each species in order to elucidate, if possible, the metabolic features that constitute an atypical organism. It was further believed that an investigation of this nature might help determine some of the fundamental biological relationships that must surely exist between organisms within a genus. This paper, then, is a report upon the comparative metabolism of all species and types within the genus Brucella.