In vivo and in vitro demonstration that Staphylococcus aureus is an intracellular pathogen in the presence or absence of fibronectin-binding proteins

ABSTRACT The fibronectin-binding proteins (FnBPs) of Staphylococcus aureus are believed to be implicated in the pathogen's adherence to and colonization of bovine mammary glands, thus leading to infectious mastitis. In vitro studies have shown that FnBPs help the adhesion of the pathogen to bovine mammary epithelial cells. However, the importance of FnBPs for the infection of mammary glands has never been directly established in vivo. In this study with a mouse model of mastitis, the presence of FnBPs on the surface of S. aureus increased the capacity of the bacterium to colonize mammary glands under suckling pressure compared to that of a mutant lacking FnBPs.

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Increased Virulence of a Fibronectin-Binding Protein Mutant of Staphylococcus aureus in a Rat Model of Pneumonia

Infection and Immunity ◽

10.1128/iai.70.7.3865-3873.2002 ◽

2002 ◽

Vol 70 (7) ◽

pp. 3865-3873 ◽

Cited By ~ 42

Author(s):

Mary C. McElroy ◽

David J. Cain ◽

Christine Tyrrell ◽

Timothy J. Foster ◽

Christopher Haslett

Keyword(s):

Staphylococcus Aureus ◽

Epithelial Cells ◽

Rat Model ◽

Binding Proteins ◽

Binding Protein ◽

Alveolar Epithelial Cells ◽

Alveolar Epithelial ◽

Fibronectin Binding Protein ◽

Fibronectin Binding

ABSTRACT Fibronectin-binding proteins mediate Staphylococcus aureus internalization into nonphagocytic cells in vitro. We have investigated whether fibronectin-binding proteins are virulence factors in the pathogenesis of pneumonia by using S. aureus strain 8325-4 and isogenic mutants in which fibronectin-binding proteins were either deleted (DU5883) or overexpressed [DU5883(pFnBPA4)]. We first demonstrated that fibronectin-binding proteins mediate S. aureus internalization into alveolar epithelial cells in vitro and that S. aureus internalization into alveolar epithelial cells requires actin rearrangement and protein kinase activity. Second, we established a rat model of S. aureus-induced pneumonia and measured lung injury and bacterial survival at 24 and 96 h postinoculation. S. aureus growth and the extent of lung injury were both increased in rats inoculated with the deletion mutant (DU5883) in comparison with rats inoculated with the wild-type (8325-4) and the fibronectin-binding protein-overexpressing strain DU5883(pFnBPA4) at 24 h postinfection. Morphological evaluation of infected lungs at the light and electron microscopic levels demonstrated that S. aureus was present within neutrophils from both 8325-4- and DU5883-inoculated lungs. Our data suggest that fibronectin-binding protein-mediated internalization into alveolar epithelial cells is not a virulence mechanism in a rat model of pneumonia. Instead, our data suggest that fibronectin-binding proteins decrease the virulence of S. aureus in pneumonia.

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Fibrinogen and fibronectin binding cooperate for valve infection and invasion in Staphylococcus aureus experimental endocarditis

Journal of Experimental Medicine ◽

10.1084/jem.20050125 ◽

2005 ◽

Vol 201 (10) ◽

pp. 1627-1635 ◽

Cited By ~ 189

Author(s):

Yok-Ai Que ◽

Jacques-Antoine Haefliger ◽

Lionel Piroth ◽

Patrice François ◽

Eleonora Widmer ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Binding Domain ◽

Disease Evolution ◽

Cell Internalization ◽

Fibrinogen Binding ◽

In Trans ◽

Fibronectin Binding ◽

In Cis

The expression of Staphylococcus aureus adhesins in Lactococcus lactis identified clumping factor A (ClfA) and fibronectin-binding protein A (FnBPA) as critical for valve colonization in rats with experimental endocarditis. This study further analyzed their role in disease evolution. Infected animals were followed for 3 d. ClfA-positive lactococci successfully colonized damaged valves, but were spontaneously eradicated over 48 h. In contrast, FnBPA-positive lactococci progressively increased bacterial titers in vegetations and spleens. At imaging, ClfA-positive lactococci were restricted to the vegetations, whereas FnBPA-positive lactococci also invaded the adjacent endothelium. This reflected the capacity of FnBPA to trigger cell internalization in vitro. Because FnBPA carries both fibrinogen- and fibronectin-binding domains, we tested the role of these functionalities by deleting the fibrinogen-binding domain of FnBPA and supplementing it with the fibrinogen-binding domain of ClfA in cis or in trans. Deletion of the fibrinogen-binding domain of FnBPA did not alter fibronectin binding and cell internalization in vitro. However, it totally abrogated valve infectivity in vivo. This ability was restored in cis by inserting the fibrinogen-binding domain of ClfA into truncated FnBPA, and in trans by coexpressing full-length ClfA and truncated FnBPA on two separate plasmids. Thus, fibrinogen and fibronectin binding could cooperate for S. aureus valve colonization and endothelial invasion in vivo.

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Impacts of sarA and agr in Staphylococcus aureus Strain Newman on Fibronectin-Binding Protein A Gene Expression and Fibronectin Adherence Capacity In Vitro and in Experimental Infective Endocarditis

Infection and Immunity ◽

10.1128/iai.72.3.1832-1836.2004 ◽

2004 ◽

Vol 72 (3) ◽

pp. 1832-1836 ◽

Cited By ~ 45

Author(s):

Yan-Qiong Xiong ◽

Arnold S. Bayer ◽

Michael R. Yeaman ◽

Willem van Wamel ◽

Adhar C. Manna ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Binding Capacity ◽

Protein A ◽

Aureus Strain ◽

Global Regulators ◽

Fibronectin Binding Protein ◽

Regulatory Loci ◽

Fibronectin Binding

ABSTRACT We investigated the impacts of sarA and agr on fnbA expression and fibronectin-binding capacity in Staphylococcus aureus in vitro and in experimental endocarditis. Although sarA up-regulated and agr down-regulated both fnbA expression and fibronectin binding in vitro and in vivo, fnbA expression was positively regulated in the absence of both global regulators. Thus, additional regulatory loci contribute to fnbA regulation and fibronectin-binding capacities in S. aureus.

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Disparity in the In Vitro versus In Vivo Regulation of Fibronectin‐Binding Proteins by 2 Global Regulators,saeRSandsigB, inStaphylococcus aureus

The Journal of Infectious Diseases ◽

10.1086/606011 ◽

2009 ◽

Vol 200 (9) ◽

pp. 1371-1374 ◽

Cited By ~ 4

Author(s):

Ambrose L. Cheung ◽

Soo‐Jin Yang ◽

Arnold S. Bayer ◽

Yan Q. Xiong

Keyword(s):

Binding Proteins ◽

Global Regulators ◽

Fibronectin Binding

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Shear Stress Prevents Fibronectin Binding Protein-Mediated Staphylococcus aureus Adhesion to Resting Endothelial Cells

Infection and Immunity ◽

10.1128/iai.69.5.3472-3475.2001 ◽

2001 ◽

Vol 69 (5) ◽

pp. 3472-3475 ◽

Cited By ~ 24

Author(s):

Kesav Reddy ◽

Julia M. Ross

Keyword(s):

Staphylococcus Aureus ◽

Endothelial Cells ◽

Shear Stress ◽

Endothelial Cell ◽

Binding Proteins ◽

Mechanical Forces ◽

Cell Surfaces ◽

Fibronectin Binding Protein ◽

Fibronectin Binding

ABSTRACT Fibronectin binding proteins (FnBP) on the surface ofStaphylococcus aureus have previously been shown to mediate adherence of the organism to resting endothelial cells in static adhesion assays. However, in this study using well-defined flow assays, we demonstrate that physiologic levels of shear stress prevent FnBP-mediated adhesion of S. aureus 8325-4 to resting endothelial cells. This result suggests that mechanical forces present in vivo may influence the ability of staphylococci to bind endothelial cell surfaces.

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Reassessing the Role of Staphylococcus aureus Clumping Factor and Fibronectin-Binding Protein by Expression in Lactococcus lactis

Infection and Immunity ◽

10.1128/iai.69.10.6296-6302.2001 ◽

2001 ◽

Vol 69 (10) ◽

pp. 6296-6302 ◽

Cited By ~ 115

Author(s):

Yok-Ai Que ◽

Patrice François ◽

Jacques-Antoine Haefliger ◽

José-Manuel Entenza ◽

Pierre Vaudaux ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Lactococcus Lactis ◽

Gene Knockout ◽

Binding Protein ◽

Single Gene ◽

Fibronectin Binding Protein ◽

Fibronectin Binding

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, bothclfA and fnbA increased the adherence of lactococci to their specific ligands to a similar extent as theS. aureus gene donor. In vivo, the minimum inoculum size producing endocarditis in ≥80% of the rats (80% infective dose [ID80]) with the parent lactococcus was ≥107CFU. In contrast, clfA-expressing andfnbA-expressing lactococci required only 105CFU 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 = 104 to 105 CFU) in this model. The results confirmed the role ofclfA 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 theclfA and fnbA products should be blocked for the therapy to be effective.

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Role of Fibronectin-Binding Proteins A and B inIn VitroCellular Infections andIn VivoSeptic Infections by Staphylococcus aureus

Infection and Immunity ◽

10.1128/iai.00133-11 ◽

2011 ◽

Vol 79 (6) ◽

pp. 2215-2223 ◽

Cited By ~ 53

Author(s):

Hitomi Shinji ◽

Yukio Yosizawa ◽

Akiko Tajima ◽

Tadayuki Iwase ◽

Shinya Sugimoto ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Protein A ◽

Severe Infection ◽

Nuclear Factor Κb ◽

Phagocytic Cells ◽

Content Type ◽

Fibronectin Binding

ABSTRACTFibronectin-binding protein A (FnBPA) and FnBPB are important adhesins forStaphylococcus aureusinfection. We constructedfnbAand/orfnbBmutant strains fromS. aureusSH1000, which possesses intactrsbU, and studied the role of these adhesins inin vitroandin vivoinfections. In intravenous infection, allfnbmutants caused a remarkable reduction in the colonization rate in kidneys and the mortality rate of mice.fnbBmutant caused a more severe decrease in body weight than that caused byfnbAmutant. Serum levels of interleukin-6 and nuclear factor κB (NF-κB) activation in spleen cells were remarkably reduced infnbAorfnbA fnbBmutant infections; however, there was no significant reduction infnbBmutant infections. Inin vitrocellular infection, FnBPA was shown to be indispensable for adhesion to and internalization by nonprofessional phagocytic cells upon ingestion by inflammatory macrophages and NF-κB activation. However, both FnBPs were required for efficient cellular responses. The results showed that FnBPA is more important forin vitroandin vivoinfections; however, cooperation between FnBPA and FnBPB is indispensable for the induction of severe infection resulting in septic death.

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The Fibrinogen- and Fibronectin-Binding Domains of Staphylococcus aureus Fibronectin-Binding Protein A Synergistically Promote Endothelial Invasion and Experimental Endocarditis

Infection and Immunity ◽

10.1128/iai.00405-08 ◽

2008 ◽

Vol 76 (8) ◽

pp. 3824-3831 ◽

Cited By ~ 63

Author(s):

Lionel Piroth ◽

Yok-Ai Que ◽

Eleonora Widmer ◽

Alexandre Panchaud ◽

Stéphane Piu ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Amino Acid ◽

Binding Protein ◽

Protein A ◽

Binding Domains ◽

Fibrinogen Binding ◽

Fibronectin Binding Protein ◽

Fibronectin Binding

ABSTRACT Staphylococcus aureus experimental endocarditis relies on sequential fibrinogen binding (for valve colonization) and fibronectin binding (for endothelial invasion) conferred by peptidoglycan-attached adhesins. Fibronectin-binding protein A (FnBPA) reconciles these two properties—as well as elastin binding—and promotes experimental endocarditis by itself. Here we attempted to delineate the minimal subdomain of FnBPA responsible for fibrinogen and fibronectin binding, cell invasion, and in vivo endocarditis. A large library of truncated constructs of FnBPA was expressed in Lactococcus lactis and tested in vitro and in animals. A 127-amino-acid subdomain spanning the hinge of the FnBPA fibrinogen-binding and fibronectin-binding regions appeared necessary and sufficient to confer the sum of these properties. Competition with synthetic peptides could not delineate specific fibrinogen- and fibronectin-binding sites, suggesting that dual binding arose from protein folding, irrespective of clearly defined binding domains. Moreover, coexpressing the 127-amino-acid subdomain with remote domains of FnBPA further increased fibrinogen binding by ≥10 times, confirming the importance of domain interactions for binding efficacy. In animals, fibrinogen binding (but not fibronectin binding) was significantly associated with endocarditis induction, whereas both fibrinogen binding and fibronectin binding were associated with disease severity. Moreover, fibrinogen binding also combined with fibronectin binding to synergize the invasion of cultured cell lines significantly, a feature correlating with endocarditis severity. Thus, while fibrinogen binding and fibronectin binding were believed to act sequentially in colonization and invasion, they appeared unexpectedly intertwined in terms of both functional anatomy and pathogenicity (in endocarditis). This unforeseen FnBPA subtlety might bear importance for the development of antiadhesin strategies.

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Cu(II) coordination polymer: treatment effect on catheter-associated urinary tract infectious via suppressing Staphylococcus aureus growth in vitro and in vivo

Inorganic and Nano-Metal Chemistry ◽

10.1080/24701556.2020.1835970 ◽

2020 ◽

pp. 1-5

Author(s):

Zhi-Wang Tang ◽

Xu-Zhong Liu ◽

Ai-Di Ma ◽

Lu Ji

Keyword(s):

Staphylococcus Aureus ◽

Urinary Tract ◽

Coordination Polymer ◽

Treatment Effect

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