VMC 211: General Veterinary Microbiology (1+1)

PILI (FIMBRIAE)

• They are hollow, non helical, filamentous appendages. They are shorter, thinner and more numerous than flagella. They are not involved in motility.They composed of a protein monomer called pilin.
• Pili are found in both motile and non motile bacteria. They play a major role in attachment of bacteria to epithelial cells lining the respiratory, intestinal and genitourinary tracts.
• This helps bacteria from being washed away by the flow of mucous or body fluids and permits infection to be established. Sex pili are involved in conjugation.