Urease activity of Brucella species.

Examination of the urease activity of 604 brucella strains showed a limited correlation with species. Most strains of B canis, B neotomae and B suis gave a positive urease reaction within 15 minutes, although some exceptions were noted. A substantial proportion of strains of B abortus and B melitensis also hydrolysed urea as rapidly as most B suis strains. Although most B ovis strains were negative to the urease test, 28.9 per cent of those examined gave positive reactions.

Disc electrophoresis of phenol:acetic acid:water-soluble proteins for the identification of Yersinia species.

Disc electrophoresis of phenol:acetic acid:water extracts of Yersinia pestis, Y produced pseudotuberculosis, Y enterocolitica, Y philomiragia and Y ruckeri protein separation patterns characteristic of each species. The patterns produced by Y pestis, Y pseudotuberculosis, Y enterocolitica and Y ruckeri showed features in common. Those given by Y philomiragia strains were quite distinctive and showed little similarity to the other Yersinia species. All Y enterocolitica strains produced similar patterns irrespective of biochemical properties. Strains classified as Y intermedia or Y enterocolitica-like produced patterns indistinguishable from those given by Y enterocolitica.