Virulence

Definition

Virulence is the degree of pathogenicity of a microorganism, indicating how severe the disease it can cause. It encompasses factors like toxin production, adhesion capability, and immune evasion strategies.

5 Must Know Facts For Your Next Test

1. Virulence factors include toxins, enzymes, and other molecules that enhance a pathogen's ability to cause disease.
2. The higher the virulence of a pathogen, the more severe the symptoms and damage to the host organism.
3. Pathogens with high virulence often have mechanisms to evade or suppress the host's immune response.
4. Virulence can be quantified by measures such as LD50 (lethal dose for 50% of hosts) and ID50 (infectious dose for 50% of hosts).
5. Horizontal gene transfer can spread virulence factors between microbial species, contributing to increased pathogenicity.

Review Questions

Related terms

Pathogenicity:

The ability of an organism to cause disease.

Toxigenicity: The capacity of a microorganism to produce toxins.

Adhesion Factors: Molecules that enable pathogens to attach to host cells.