[Microbes: pathogen or no pathogen?]

The pathogenic activity of a microorganism in a host depends on its genome, of the environmental factors that it is and of the immunity of the host. The recent advances are studied in the first two factors, so much the denominated "pathogenicity islands", that condition the virulence, as the external factors (temperature, pH, concentrations of metals, etc.) that they allow or not the development of this pathogenic capacity. The new genetics knowledge and molecular microbiology will allow important advances in the pathogenesis, diagnosis, treatment, epidemiology and prevention of the illness caused by biological agents.