Identification of a novel protein promoting the colonization and survival of Finegoldia magna, a bacterial commensal and opportunistic pathogen.
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.
Frick
Inga-Maria
IM
Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden. Inga-Maria.Frick@med.lu.se
Karlsson
Christofer
C
Mörgelin
Matthias
M
Olin
Anders I
AI
Janjusevic
Radmila
R
Hammarström
Clara
C
Holst
Elisabet
E
de Château
Maarten
M
Björck
Lars
L
D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001485:Basement Membrane / Q000382:microbiology; D054804:Cathelicidins; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006095:Gram-Positive Cocci / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009894:Opportunistic Infections / Q000382:microbiology; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012867:Skin / Q000382:microbiology*; D020349:Surface Plasmon Resonance
D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D054804:Cathelicidins