Virulence
The degree of pathogenicity of a microorganism—how much damage it causes to a host. Highly virulent pathogens cause severe disease; low-virulence pathogens cause mild or no symptoms.
Used in the Books
This term appears in 2 chapters:
"...osses threshold → gene expression changes → bioluminescence Pseudomonas aeruginosa (opportunistic pathogen): - Uses quorum sensing to coordinate virulence factor production - At low density: Don't produce toxins (would alert immune system without overwhelming it) - At high density (quorum reached): Prod..."
"The switch is density-dependent and automatic - no decision-making required, just chemistry. Pseudomonas aeruginosa: Coordinating Virulence Pseudomonas aeruginosa, a pathogenic bacterium that infects wounds, lungs (especially in cystic fibrosis patients), and burns, uses quorum sensing..."
Biological Context
Virulence is an evolved trait balancing pathogen interests: more virulent strains exploit hosts more intensely but may kill them before transmission. The evolution of virulence depends on transmission mode, host immunity, and whether multiple pathogen strains coinfect the same host.