[Isolation of "Brucella suis" biotype 5 from a bitch, in Madagascar. Validity of the species name "Brucella canis" (author's transl)].

A Gram-negative organism isolated from a btich, in Madagascar, was examined by bacteriologic, immunologic and metabolic methods, in parallel with cultures representative of the Brucella species. The organism fits well into the genus Brucella on the basis of its growth, biochemical and antigenic characteristics and was found to have the metabolic pattern on L-asparagine (-), L-arginine (+) and DL-ornithine (+) that identifies and defines the species Brucella suis. It is of rough colonial morphology and electron microscopy showed a cell wall structure similar to that of other rough Brucella. By all the other recommended criteria for btotype identification it was found to be similar to Brucella suis biotype 5 best known as Brucella canis. In contrast to the strains of this biotype, it grows on basic fuchsin at 20 mug/ml and on safranine O at 200 mug/ml. These differences obtained with just one strain would not justify by now the proposal for a new biotype. We favor the designation Brucella suis biotype 5 proposed by Meyer, and the validity of Brucella canis (Carmichael and Bruner) as a separate species is discussed. It is the first strain of Brucella isolated in Madagascar.