Pathogen evolution is a key factor determining the spread and severity of infectious diseases. The aim of this article is to study the genetic adaptations of pathogens and their impact on the pathogenesis and dynamics of infectious diseases in humans and animals. The article discusses the mechanisms of mutations, horizontal gene transfer and other processes that contribute to the emergence of pathogen resistance to drugs and host immune responses. The research methodology includes a comparative analysis of pathogen genomic data, which allows us to identify patterns of their adaptation in response to changing environmental conditions and therapeutic effects. The results show that pathogens actively adapt to antibiotics and antiviral drugs, as well as to the host immune system, which increases the likelihood of epidemics and complicates the fight against infections. One of the key findings of the study is the need to monitor genetic changes in pathogens to develop effective preventive and therapeutic measures. The contribution of the study is to understand the mechanisms of rapid adaptation of pathogens, which is important for epidemiology and medicine. However, the study is limited by the difficulty of predicting long-term evolutionary changes and the influence of ecosystem factors that can accelerate or slow down pathogen adaptation. Practical implications include the need to update treatment protocols and develop new drugs that can overcome pathogen resistance. Social implications affect the health care system, as increased pathogen resistance can lead to increased economic costs and mortality.

Pathogen evolution, genetic adaptations, infectious diseases, antibiotic resistance, horizontal gene transfer, mutations, epidemiology, immune system, pathogen monitoring.

Smith, J.A.; Johnson, L. B.; White, R. D. Evolution of Pathogen Resistance: Genetic Adaptations and Their Impact on Infectious Diseases. Infect. Dis. Rev. 2023, 45(2), 123–145.

Ivanov , IA; Petrov , P. P. Mechanisms of Antimicrobial Resistance in Bacteria. *J. Microbiol . 2021, 39(4), 555–572.

Lee, CH; Kim, Y.J.; Park, J. H. Metabolic Adaptations of Pathogens: A Review. Front. Microbiol . 2022, 13, 879–895.

Gonzalez, MA; Rodríguez, J.M.; Santos, L. B. Pathogen-Host Interactions: The Role of Immune Evasion Strategies. Immunology Today 2020, 41(8), 653–660.

Kwon, H.S.; Choi, S.Y.; Lee, JK Genetic Variability and Pathogenicity of Staphylococcus aureus : Implications for Therapy. J. Infect. Dis. 2021, 223(5), 765–775.