Genome Instability of the Cholera Agent: Role in the Evolution of Pathogenicity, Drug Resistance, and Adaptation to a Changing Environment

Cholera, which has claimed millions of human lives, continues to pose a particular danger, since the evolution of the genome of the pathogen causing the current seventh pandemic has resulted in the emergence of genetically modified strains with increased pathogenic and epidemic potential. A review of current data on the genome instability of Vibrio cholerae biovar El Tor associated with the presence of various mobile genetic elements is presented. The molecular-genetic mechanisms underlying the evolution of the pathogen in the modern period are considered. The role of horizontal gene transfer and subsequent mutations in the emergence of new variants of the pathogen with altered genes of pathogenicity, antibiotic resistance, and pandemicity is shown. The biological consequences of these changes in the genome associated with the enhancement of the virulence properties of modern variants of the pathogen, the emergence of multiple drug resistance, and their widespread distribution are discussed. Several priority areas in further research of the pathogen at the genomic, transcriptomic, and proteomic levels are also presented.