**4. Conclusion**

*Vibrio*, as a kind of human and animal pathogen, exists widely in the world, and its increasing number and pathogenicity are great challenges to human public health and healthy aquaculture. The changes of *Vibrio* community in the environment are related to abiotic factors (temperature, salinity, pH, water depth, dissolved oxygen, transparency, nutrient concentration, etc.) and biological factors (protozoa, viruses, marine animals and algae, etc.), among which temperature and salinity are considered to be the most important factors affecting the changes of *Vibrio* community, but in temperate regions where salinity and temperature are relatively stable, nutrient concentration and phytoplankton community contribute more to the changes of *Vibrio* community. In recent years, with the outbreak of *Vibrio* in some areas caused by climate change and rising seawater temperature, the number of some pathogenic *Vibrio* began to increase. The pathogenicity of *Vibrio* is related to virulence factors encoded by virulence genes (adhesion factors, cytotoxins, extracellular enzymes, capsular polysaccharides, iron uptake system, etc.), and different virulence factors play different roles in the infection process. In this chapter, the influencing factors of *Vibrio* community change and various virulence factors of *Vibrio* in the process of infecting the host were summarized, in order to provide reference and help for human public health and aquaculture industry.

*Infections and Sepsis Development*
