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Surface proteins of Finegoldia magna interacting with the human host

Karlsson, Christofer LU (2008) In Lund University, Faculty of Medicine Doctoral Dissertation Series 2008:134.
Abstract
Finegoldia magna is a Gram-positive anaerobe and a member of the normal human microflora. This bacterium is also an opportunistic pathogen and isolated from ~10% of all anaerobic infections. Reoccurring taxonomical changes and the anaerobic growth have contributed to the neglect of F. magna. The present thesis describes the identification and characterization of two novel surface proteins of F. magna.



One of the identified proteins, SufA, is a protease belonging to the subtilase family. This protease cleaves and inactivates the antimicrobial peptide LL-37 and the antibacterial chemokine MIG/CXCL9. Furthermore, the protease cleaves fibrinogen and thereby inhibits fibrin network formation. To our knowledge, the first... (More)
Finegoldia magna is a Gram-positive anaerobe and a member of the normal human microflora. This bacterium is also an opportunistic pathogen and isolated from ~10% of all anaerobic infections. Reoccurring taxonomical changes and the anaerobic growth have contributed to the neglect of F. magna. The present thesis describes the identification and characterization of two novel surface proteins of F. magna.



One of the identified proteins, SufA, is a protease belonging to the subtilase family. This protease cleaves and inactivates the antimicrobial peptide LL-37 and the antibacterial chemokine MIG/CXCL9. Furthermore, the protease cleaves fibrinogen and thereby inhibits fibrin network formation. To our knowledge, the first example of directed mutagenesis of F. magna is presented with the disruption of the sufA gene.



The other identified protein is FAF. This is a cell wall attached α-helical protein that forms hair-like projections on the bacterial surface. FAF is self-associating and contributes to bacterial clumping. FAF also mediates adhesion of the bacterium to basement membranes of human skin by interacting with BM-40. A further function of FAF is blocking of the activity of antimicrobial peptides. The genes encoding faf and sufA are present in a majority of investigated isolates indicating that the proteins have important functions.



In conclusion, the findings presented in this thesis may help explain how F. magna colonizes the human host and causes opportunistic infections. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Dr O'Toole, Paul W., Department of Microbiology & Alimentary Pharmabiotic Centre, University College Cork, Ireland
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Finegoldia magna, Gram-positive anaerobic cocci, surface proteins, protease, LL-37, MIG/CXCL9, Fibrinogen, adhesion, gene disruption, bacterial aggregation, basement membranes
in
Lund University, Faculty of Medicine Doctoral Dissertation Series
volume
2008:134
pages
38 pages
publisher
Department of Clinical Sciences, Lund University
defense location
Rune Grubb-salen, Biomedicinskt Centrum, Sölvegatan 18, 22184 Lund
defense date
2008-12-19 09:15
ISSN
1652-8220
ISBN
978-91-86059-87-3
language
English
LU publication?
yes
id
557f4036-af5c-4a53-b670-706720bd508c (old id 1270155)
date added to LUP
2008-11-24 09:58:32
date last changed
2016-09-19 08:44:50
@phdthesis{557f4036-af5c-4a53-b670-706720bd508c,
  abstract     = {Finegoldia magna is a Gram-positive anaerobe and a member of the normal human microflora. This bacterium is also an opportunistic pathogen and isolated from ~10% of all anaerobic infections. Reoccurring taxonomical changes and the anaerobic growth have contributed to the neglect of F. magna. The present thesis describes the identification and characterization of two novel surface proteins of F. magna.<br/><br>
<br/><br>
One of the identified proteins, SufA, is a protease belonging to the subtilase family. This protease cleaves and inactivates the antimicrobial peptide LL-37 and the antibacterial chemokine MIG/CXCL9. Furthermore, the protease cleaves fibrinogen and thereby inhibits fibrin network formation. To our knowledge, the first example of directed mutagenesis of F. magna is presented with the disruption of the sufA gene.<br/><br>
<br/><br>
The other identified protein is FAF. This is a cell wall attached α-helical protein that forms hair-like projections on the bacterial surface. FAF is self-associating and contributes to bacterial clumping. FAF also mediates adhesion of the bacterium to basement membranes of human skin by interacting with BM-40. A further function of FAF is blocking of the activity of antimicrobial peptides. The genes encoding faf and sufA are present in a majority of investigated isolates indicating that the proteins have important functions. <br/><br>
<br/><br>
In conclusion, the findings presented in this thesis may help explain how F. magna colonizes the human host and causes opportunistic infections.},
  author       = {Karlsson, Christofer},
  isbn         = {978-91-86059-87-3},
  issn         = {1652-8220},
  keyword      = {Finegoldia magna,Gram-positive anaerobic cocci,surface proteins,protease,LL-37,MIG/CXCL9,Fibrinogen,adhesion,gene disruption,bacterial aggregation,basement membranes},
  language     = {eng},
  pages        = {38},
  publisher    = {Department of Clinical Sciences, Lund University},
  school       = {Lund University},
  series       = {Lund University, Faculty of Medicine Doctoral Dissertation Series},
  title        = {Surface proteins of Finegoldia magna interacting with the human host},
  volume       = {2008:134},
  year         = {2008},
}