Brucella taxonomy and evolution.

Taxonomy and nomenclature represent man-made systems designed to enhance understanding of the relationship between organisms by comparison of discrete sets of properties. Initial efforts at bacterial taxonomy were flawed as a result of the previous use of nonsystematic approaches including common names resulting in confusing and inaccurate nomenclature. A decision was made to start afresh with bacterial nomenclature and to avoid the hazards experienced in the taxonomic classification of higher organisms. This was achieved by developing new rules designed to simplify classification and avoid unnecessary and confusing changes. This article reviews the work of a number of scientists attempting to reconcile new molecular data describing the phylogenetic relationship between Brucella organisms and a broader family of organisms with widely variant phenotypes that include human virulence and host range against a backdrop of strict regulatory requirements that fail to recognize significant differences between organisms with similar nomenclature.