Which virulence factor(s) of Fusobacterium are cited as primary mediators of its adhesive and invasive properties?

• A. FadA
• B. Fusobacterial autotransporter protein 2
• C. Fusobacterial outer membrane protein A
• D. FadA, fusobacterial autotransporter protein 2, and fusobacterial outer membrane protein A

Answer: (D)

Fusobacterium nucleatum relies on multiple surface proteins to stick to and penetrate host tissues. FadA is a well-characterized adhesin/invasin that binds to E-cadherin on epithelial cells, disrupting junctions and activating signaling pathways that promote internalization and inflammation. The fusobacterial outer membrane protein A (FomA) adds another layer of adhesion and invasion, also modulating host immune interactions. The fusobacterial autotransporter protein 2 functions as an additional adhesin, enabling binding to host cell surfaces and facilitating tissue invasion. Because each of these factors contributes to the bacterium’s ability to adhere and invade, they’re all cited as primary mediators of adhesive and invasive properties.