[Heterogeneity of the population of pseudotuberculosis microbe cultures]

Use of the method of oblique illumination of the colonies permitted to detect four variants of pseudotuberculosis microbe differing by the character of fluorescence, and also by virulence, toxicity and immunogenicity. Strains isolated from sick persons, carriers and rodents were characterized by polychromatic character of fluorescence of the colonies, whereas strains isolated from the external environment were monochromatic. Since colonies with a different fluorescence had different biological properties it can be supposed that the properties of each strain as a whole were determined by its quantitative and qualitative composition as of a heterogeneous population.