• Open Access

Identification of a novel protein promoting the colonization and survival of Finegoldia magna, a bacterial commensal and opportunistic pathogen


  • Present addresses: Laboratory of Structural Microbiology, TheRockefeller University, 1230 York Avenue, New York, NY 10065, USA;Department of Pathology, Rikshospitalet University Hospital, N-0027 Oslo, Norway;§Nordic Clinical Research Unit (CRU), Sanofi-Aventis, Box 14142, 167 14, Bromma, Sweden.

    Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

*E-mail Inga-Maria.Frick@med.lu.se; Tel. (+46) 46 2228569; Fax (+46) 46 157756.


Anaerobic bacteria dominate the human normal microbiota, but strikingly little is known about these commensals. Finegoldia magna is a Gram-positive anaerobe found in the skin and at other non-sterile body surfaces, but it is also an opportunistic pathogen. This study describes a novel protein designated FAF (F. magna adhesion factor) and expressed by more than 90% of F. magna isolates. The protein is present in substantial quantities at the F. magna surface but is also released from the surface. FAF forms large protein aggregates in solution and surface-associated FAF causes bacterial clumping. In skin F. magna bacteria were localized to the epidermis, where they adhere to basement membranes. FAF was found to mediate this adhesion via interactions with BM-40, a basement membrane protein. The biological significance of FAF is further underlined by the observation that it blocks the activity of LL-37, a major human antibacterial peptide. Altogether, the data demonstrate that FAF plays an important role in colonization and survival of F. magna in the human host.