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

Détails

ID Serval
serval:BIB_3E9690413C5C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Reassessing the role of Staphylococcus aureus clumping factor and fibronectin-binding protein by expression in Lactococcus lactis.
Périodique
Infection and Immunity
Auteur(s)
Que Y.A., François P., Haefliger J.A., Entenza J.M., Vaudaux P., Moreillon P.
ISSN
0019-9567 (Print)
ISSN-L
0019-9567
Statut éditorial
Publié
Date de publication
2001
Volume
69
Numéro
10
Pages
6296-6302
Langue
anglais
Résumé
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.
Mots-clé
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
Oui
Création de la notice
07/04/2008 8:46
Dernière modification de la notice
20/08/2019 14:35
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