Heterogeneity in isogenic bacteria populations and modern technologies of cell phenotyping

In the framework of the modern microbiological paradigm, colonies of genetically identical microorganisms are considered as biosocial systems consisting of several heterogeneous clonal cell clusters (bacterial phenotypes) that respond differently to changes in the environment. Phenotypic heterogeneity was found in recent decades in all isogenic populations of pathogenic bacteria. Such heterogeneity provides a selective advantage of cellular phenotypes with changes in the physicochemical parameters of the environment and competitive interaction with other microorganisms. Heterogeneity in bacterial communities is of great importance for the survival of pathogenic bacteria in the host organism, the progression and persistence of infections, as well as the decrease in the effectiveness of antibiotic therapy. The modern spectrum of analytical tools for studying cellular phenotyping is presented both by optical imaging methods and qualitative structural characteristics of single cells, and by omix technologies of quantitative analysis and monitoring of molecular intracellular processes. These diverse tools make it possible not only to identify and modulate phenotypic heterogeneity in isogenic bacterial populations, but also to evaluate the functional significance of cellular phenotypes in the development of the infectious process. The aim of the review is the integration of modern concepts of heterogeneity in isogenic bacterial populations, with an emphasis on the presentation of modern analytical technologies for assessing and monitoring phenotypic typing of single cells.