[Modification of lipopolysaccharides as one of the ways of adaptation of pathogenic bacteria and their populations to biotic and abiotic environmental factors].
The review is devoted to a problem of adaptive role of lipopolysaccharide (LPS) modification of pathogenic bacteria cells. The biological activity of LPS depends on their molecular conformation, which is determined by primary structure and charges of their molecules and can change through regulation of enzyme activity of LPS separate component synthesis. Regulation of gene expression, which determines LPS synthesis, can occur at a level of DNA primary structure (through mutations and recombinations); on highest levels of DNA organization through alteration of its conformation; can be mediated by signal transduction systems of bacterial cells. The changes of LPS structure can have spontaneous character due both to the instability of the appropriate genes and to the induction under the influence of various factors. Spontaneous variation of LPS structure is one of the reasons of heterogeneity of bacterial cell populations and creates a basis of their preadaptation. The influence of the environment factors on structure and functions of LPS can be both direct and mediated through regulation of expression of chromosome and plasmid genes by direct influence of the factors on DNA and through signal transduction systems of bacterial cells. Pathogenic bacteria can use the LPS variations at adaptation to biotic and abiotic factors.