Reassessing the role of Staphylococcus aureus clumping factor and fibronectin-binding protein by expression in Lactococcus lactis.

Details

Serval ID
serval:BIB_3E9690413C5C
Type
Article: article from journal or magazin.
Collection
Publications
Title
Reassessing the role of Staphylococcus aureus clumping factor and fibronectin-binding protein by expression in Lactococcus lactis.
Journal
Infection and Immunity
Author(s)
Que Y.A., François P., Haefliger J.A., Entenza J.M., Vaudaux P., Moreillon P.
ISSN
0019-9567 (Print)
ISSN-L
0019-9567
Publication state
Published
Issued date
2001
Volume
69
Number
10
Pages
6296-6302
Language
english
Abstract
Since Staphylococcus aureus expresses multiple pathogenic factors, studying their individual roles in single-gene-knockout mutants is difficult. To circumvent this problem, S. aureus clumping factor A (clfA) and fibronectin-binding protein A (fnbA) genes were constitutively expressed in poorly pathogenic Lactococcus lactis using the recently described pOri23 vector. The recombinant organisms were tested in vitro for their adherence to immobilized fibrinogen and fibronectin and in vivo for their ability to infect rats with catheter-induced aortic vegetations. In vitro, both clfA and fnbA increased the adherence of lactococci to their specific ligands to a similar extent as the S. aureus gene donor. In vivo, the minimum inoculum size producing endocarditis in > or =80% of the rats (80% infective dose [ID80]) with the parent lactococcus was > or =10(7) CFU. In contrast, clfA-expressing and fnbA-expressing lactococci required only 10(5) CFU to infect the majority of the animals (P < 0.00005). This was comparable to the infectivities of classical endocarditis pathogens such as S. aureus and streptococci (ID80 = 10(4) to 10(5) CFU) in this model. The results confirmed the role of clfA in endovascular infection, but with a much higher degree of confidence than with single-gene-inactivated staphylococci. Moreover, they identified fnbA as a critical virulence factor of equivalent importance. This was in contrast to previous studies that produced controversial results regarding this very determinant. Taken together, the present observations suggest that if antiadhesin therapy were to be developed, at least both of the clfA and fnbA products should be blocked for the therapy to be effective.
Keywords
Adhesins, Bacterial/genetics, Adhesins, Bacterial/physiology, Amino Acid Sequence, Animals, Bacterial Adhesion, Bacterial Proteins/genetics, Bacterial Proteins/physiology, Blood Platelets/metabolism, Carrier Proteins/genetics, Carrier Proteins/physiology, Coagulase/genetics, Coagulase/physiology, Disease Models, Animal, Endocarditis, Bacterial/microbiology, Female, Fibrin/metabolism, Fibrinogen/metabolism, Fibronectins/metabolism, Gene Expression, Humans, Lactococcus lactis/genetics, Lactococcus lactis/pathogenicity, Molecular Sequence Data, Rats, Rats, Wistar, Staphylococcus aureus/genetics
Pubmed
Web of science
Open Access
Yes
Create date
07/04/2008 8:46
Last modification date
20/08/2019 14:35
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