Bacteria assemble a variety of structures on their cell surface, including extended fibers generally termed pili or fimbriae. These pili mediate interactions with other bacteria, the host, and the environment.

Pili often function as adhesins, dictating specific binding to and colonization of biological as well as non-biological surfaces. Pili are critical virulence factors for pathogenic bacteria, initiating infection and determining how and where bacterial colonization may occur. A variety of different classes of pili are found in prokaryotes. Pili have a diverse array of functions. Pili are essential for host colonization, virulence and pathogenesis for many bacteria and, in the case of type IV pili, can also be employed for motility across solid surfaces.

Further reading:

1. Pili and Flagella
2. Bacterial Secreted Proteins
3. Microbiology Books

Labels: adhesins, colonization, fimbriae, flagella, motility, pathogenesis, pathogenic, pili, type IV pili, virulence