The fibronectin-binding protein Fnm contributes to adherence to extracellular matrix components and virulence of Enterococcus faecium. Academic Article uri icon


  • The interaction between bacteria and fibronectin is believed to play an important role in the pathogenicity of clinically important Gram-positive cocci. In the present study, we identified a gene encoding a predicted fibronectin-binding protein of Enterococcus faecium (fnm), a homologue of Streptococcus pneumoniae pavA, in the genomes of E. faecium strain TX82 and all other sequenced E. faecium isolates. Full-length recombinant Fnm from strain TX82 bound to immobilized fibronectin in a concentration-dependent manner and also appeared to bind collagen type V and laminin, but not other proteins, such as transferrin, heparin, bovine serum albumin, mucin, or collagen IV. We demonstrated that the N-terminal fragment of Fnm is required for full fibronectin binding, since truncation of this region caused a 2.4-fold decrease (P < 0.05) in the adhesion of E. faecium TX82 to fibronectin. Deletion of fnm resulted in a significant reduction (P < 0.001) in the ability of the mutant, TX6128, to bind fibronectin relative to that of the wild-type strain; in situ reconstitution of fnm in the deletion mutant strain restored adherence. In addition, the fnm mutant was highly attenuated relative to TX82 (P 0.0001) in a mixed-inoculum rat endocarditis model. Taken together, these results demonstrate that Fnm affects the adherence of E. faecium to fibronectin and is important in the pathogenesis of experimental endocarditis.

published proceedings

  • Infect Immun

altmetric score

  • 0.5

author list (cited authors)

  • Somarajan, S. R., La Rosa, S. L., Singh, K. V., Roh, J. H., Hk, M., & Murray, B. E.

citation count

  • 13

complete list of authors

  • Somarajan, Sudha R||La Rosa, Sabina Leanti||Singh, Kavindra V||Roh, Jung H||Höök, Magnus||Murray, Barbara E

editor list (cited editors)

  • Pirofski, L.

publication date

  • December 2015