What role do adhesins play in virulence?

• A. They attach to host tissues
• B. They produce toxins
• C. They degrade antibodies
• D. They form spores

Answer: (A)

Adhesins are surface molecules that recognize and bind to receptors on host cells or components of the extracellular matrix. This binding anchors the microbe to the tissue, allowing it to resist being flushed away and to establish an infection. Attachment is often the first crucial step in virulence, paving the way for colonization, potential invasion, and biofilm formation. In contrast, toxins cause damage to host tissues, degrading antibodies represents immune evasion rather than sticking to surfaces, and spores are a dormant survival form, not a factor in attachment. So, the role of adhesins in virulence is to attach to host tissues, enabling the bacterium to colonize and persist.