Diagnostic value of a novel nutrient medium for isolation and cultivation of pathogens causing enteric yersiniosis and pseudotuberculosis

A new nutrient medium for isolation and cultivation of the causative agents of enteric yersiniosis and pseudotuberculosis was found to have advantages over Endo medium in its differentiating and inhibiting properties. This medium permitted the easy differentiation of Yersinia pseudotuberculosis from Y. enterocolitica, as well as from Escherichia coli, Shigella flexneri, Klebsiella pneumoniae, K. rhinoscleromatis, Hafnia, Enterobacter and Citrobacter by color; from Proteus inconstans by swarming. In addition, weakly swarming of P. vulgaris differed by their light bluish color and Pseudomonas aeruginosa, by the brilliance and size of colonies. Endo medium could be used only for differentiation of E. coli from lactose-negative Yersinia colonies, Klebsiella (by mucous growth) and, to a certain extent, all Proteus species (by swarming). The medium under test and the control medium inhibited the growth of Staphylococcus aureus. In contrast to Endo medium, the medium under test partially inhibited the growth of K. rhinoscleromatis and the swarming of P. inconstans. The new medium is now introduced into practice.