Role of sigmaB in the expression of Staphylococcus aureus cell wall adhesins ClfA and FnbA and contribution to infectivity in a rat model of experimental endocarditis.

Details

Serval ID
serval:BIB_9B7E2760E376
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Role of sigmaB in the expression of Staphylococcus aureus cell wall adhesins ClfA and FnbA and contribution to infectivity in a rat model of experimental endocarditis.
Journal
Infection and Immunity
Author(s)
Entenza J.M., Moreillon P., Senn M.M., Kormanec J., Dunman P.M., Berger-Bächi B., Projan S., Bischoff M.
ISSN
0019-9567[print], 0019-9567[linking]
Publication state
Published
Issued date
2005
Volume
73
Number
2
Pages
990-998
Language
english
Abstract
Isogenic Staphylococcus aureus strains with different capacities to produce sigma(B) activity were analyzed for their ability to attach to fibrinogen- or fibronectin-coated surfaces or platelet-fibrin clots and to cause endocarditis in rats. In comparison to the sigma(B)-deficient strain, BB255, which harbors an rsbU mutation, both rsbU-complemented and sigma(B)-overproducing derivatives exhibited at least five times greater attachment to fibrinogen- and fibronectin-coated surfaces and showed increased adherence to platelet-fibrin clots. No differences in adherence were seen between BB255 and a DeltarsbUVWsigB isogen. Northern blotting analyses revealed that transcription of clfA, encoding fibrinogen-binding protein clumping factor A, and fnbA, encoding fibronectin-binding protein A, were positively influenced by sigma(B). Sigma(B) overproduction resulted in a statistically significant increase in positive spleen cultures and enhanced bacterial densities in both the aortic vegetations and spleens at 16 h postinoculation. In contrast, at 72 h postinoculation, tissues infected with the sigma(B) overproducer had lower bacterial densities than did those infected with BB255. These results suggest that although sigma(B) appears to increase the adhesion of S. aureus to various host cell-matrix proteins in vitro, it has limited effect on pathogenesis in the rat endocarditis model. Sigma(B) appears to have a transient enhancing effect on bacterial density in the early stages of infection that is lost during progression.
Keywords
Adhesins, Bacterial/genetics, Adhesins, Bacterial/metabolism, Animals, Bacterial Proteins/metabolism, Cell Adhesion/physiology, Cell Wall, Endocarditis, Bacterial/metabolism, Endocarditis, Bacterial/microbiology, Fibrinogen/metabolism, Fibronectins/metabolism, Promoter Regions, Genetic, Rats, Sigma Factor/metabolism, Staphylococcus aureus/metabolism, Staphylococcus aureus/pathogenicity, alpha-Macroglobulins/metabolism
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 13:45
Last modification date
20/08/2019 15:02
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