Filamentous or elongated proteinaceous structures which extend from the cell surface
in gram-negative bacteria that contain certain types of conjugative plasmid. These
pili are the organs associated with genetic transfer and have essential roles in conjugation.
Normally, only one or a few pili occur on a given donor cell. (From Singleton & Sainsbury,
Dictionary of Microbiology and Molecular Biology, 2d ed, p675) This preferred use
of "pili" refers to the sexual appendage, to be distinguished from bacterial fimbriae
(FIMBRIAE, BACTERIAL), also known as common pili, which are usually concerned with
adhesion
Note générale sur le champ d'application :
do not confuse with COMMON PILI see FIMBRIAE, BACTERIAL