Bacterial microcolony--a possible approach for a rapid differentiation of bacteria

A method is developed for cultivating and observing bacteria in an early phase of their growth, when microcolonies were formed. The morphology of the microcolonies, including form, structure, characteristics of its periphery and center, as well as the mode of arrangement of bacteria in it and to each other proved to be typical for a species and often permitted its differentiation from the other species. Photographs are presented of typical microcolonies of S. aureus and of E. coli. A series of photographs is presented also as an illustration of the possibility to differentiate some species in the genus Streptococcus. The microcolonies observation is made 3 hours after material inoculation, that may permit a rapid bacteriological diagnosis. It is believed also, that the microcolony technique could be useful in the characterisation and identification of the species in the general bacteriology and taxonomy.