ABSTRACT
New experimental data in such research fields as molecular biology, biochemistry, genomics and others as well as the changes occurring in the medical-and-epidemiological situation in respect to a number of infectious diseases dictate the necessity to systemize and to revise the appropriate knowledge for the purpose of ensuring a more profound understanding of the processes providing a foundation for the relations within the system of "host--parasite". The article deals with modern aspects of investigating the pathogenesis of infectious diseases, i.e. issues of the genetic and of structural-and-functional organization as well as of regulation of the pathogenetic potential of microorganisms; and mechanism of antimicrobial protection of microorganisms including from the standpoint of evolutionary biology.
