What is the function of bacterial fimbriae

Fimbria (bacteriology)

Synonym: fimbria
English: fimbria

1 definition

Fimbriae are cell attachments of bacteria that are visible under an electron microscope and that mainly consist of adhesins and serve to attach the pathogens to cell surfaces.

2 microbiology

Fimbriae are thread-like proteins approx. 0.2-20 μm long and 3-10 nm in diameter, which are distributed over the entire cell surface or arranged in a polar pattern. They are thinner, shorter and in some cases less flexible than flagella and, in contrast to these, are not wavy, but straight. They differ from the pili in that they do not transport RNA or DNA. Sometimes the terms "fimbria" and "pilus" are also used synonymously.

Fimbriae are mainly found in gram-negative bacteria. They are used to mechanically attach and anchor the pathogens to cells. In addition, they play a role as recognition structures in the event of contact and mutual attachment of bacteria of the same species.

3 classification

There are more than 30 different types of fimbria, which are divided into two classes based on their sensitivity to mannose:

  • Mannose-sensitive fimbriae (MS type)
  • Mannose-resistant fimbriae (MR type)

4 clinic

Fimbriae are an important virulence factor for many types of bacteria, e.g. Escherichia coli, Bordetella pertussis, Pseudomonas aeruginosa as well as staphylococci and streptococci.