Virulence factors are molecules produced by pathogens that contribute to the pathogenicity and severity of infections. They help the microorganism invade the host, evade the immune system, and obtain nutrients.
5 Must Know Facts For Your Next Test
Virulence factors include toxins, enzymes, and other molecules that assist in pathogen survival and proliferation.
Pathogens can acquire virulence factors through horizontal gene transfer, including transformation, transduction, and conjugation.
Many virulence factors are encoded on mobile genetic elements such as plasmids or pathogenicity islands within the genome.
Examples of virulence factors include adhesins for attachment, invasins for cell entry, and antiphagocytic proteins to evade immune cells.
The presence and expression of specific virulence factors are often used to identify and categorize pathogenic strains of bacteria.
Review Questions
What are virulence factors, and why are they important for pathogens?
Name three types of molecules that can act as virulence factors.