Whatmore et al. have investigated the genetic diversity and phylogeny of the Brucella genus by multiple loci sequence typing. More than 4 kb of sequence were examined from 160 isolates. 27 sequence types can be distinguished. The clustering achieved confirms the close vicinity of B. canis with B. suis biovar 3 and 4, and the marked difference with B. suis biovar 5. The marine strains are tightly clustered by this approach. Although much less discriminatory than MLVA, MLST data provides a squeleton which will help define the relative weight which should be given to MLVA loci to provide an optimized clustering.