Postantibiotic SOS response states in E. coli intestinal microbiocenoses and their possible consequences (review)

Abstract

The study of the effects of stress on E. coli in the intestine, realized through SOS-response reactions, is important for understanding the possible consequences for microbiocenoses. Antibiotic resistance and the growth of infection with multiresistant bacterial strains increase the need to study the adaptive responses of E. coli strains. Such reactions as activation of lysogenic bacteriophages and production of colicins can be useful for suppressing virulent E. coli strains in intestinal microbiocenoses, while negative reactions, such as antibiotic efflux, pose a serious threat and continue to be studied to develop effective infection control strategies. Insufficient study of these processes at the microbiocenosis level emphasizes the importance of further research in this area. The review describes the diversity of E. coli bacteriocins and the regulation of their expression, and considers the variants of SOS-responses under the influence of unfavorable factors on bacteria. Microbiocenotic interactions under stress conditions accompanied by the induction of the SOS response are studied and schematically illustrated. Modern concepts of the risks and consequences of activation of the SOS response reactions when using antibiotics and exposed to lytic phages are formulated, and two competitive hypotheses are presented: "Colicin wars" and "Fight against bacteriophages". Of practical importance may be the formation of stable equilibrium microbiocenoses of E. coli limiting the accumulation of toxigenic or virulent strains and the study of factors disrupting this equilibrium, as well as the possibility of enhancing the effects of antibacterial compounds, anti-Escherichia vaccines and bacteriophages through the induction of colicinogeny/lysogenic bacteriophages. When using an insufficiently effective and selective antimicrobial drug, upon activation of the SOS response, it is possible to enhance the action of the antibiotic due to the production of colicins and lysogeny. However, due to the induction of the SOS response, such a situation will be negative, since cross-resistance to antibiotics may occur through the efflux mechanism. Coliflora SOS reactions should be considered in a negative light and stress factors that provoke a set of chain reactions of the SOS response of bacteria at the population level should be avoided.

Keywords

• sos response
• colicins
• e. coli