Which of the following is NOT an important function of bacterial fimbriae?

• A. Attachment
• B. Antibiotic resistance
• C. Locomotion
• D. Ion transport

Answer: (D)

Fimbriae are hair-like structures that primarily help bacteria cling to surfaces and host tissues, which is crucial for colonization and forming biofilms. This strong attachment is the main reason fimbriae matter in infections and in establishing bacterial communities. Some fimbriae, especially type IV pili, can also mediate a form of movement along surfaces called twitching motility, aiding the bacteria in reaching new areas. Additionally, certain pili function in genetic exchange between bacteria, such as transferring plasmids during conjugation, which can spread traits like antibiotic resistance. Ion transport, on the other hand, requires membrane channels that move ions across the cell membrane, not extracellular filaments. Since fimbriae do not transport ions, ion transport is not an important function of fimbriae.