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C Rydén

Publications and source records attributed to C Rydén.

At least 19 recordsLinked to original sources
PubMed2000

A bone sialoprotein-binding protein from Staphylococcus aureus: a member of the staphylococcal Sdr family.

Staphylococcus aureus bacteria, isolated from bone and joint infections, specifically interact with bone sialoprotein (BSP), a glycoprotein of bone and dentine extracellular matrix, via a cell-surface protein of M(r) 97000 [Yacoub, Lindahl, Rubin, Wendel, Heinegârd and Rydén, (1994) Eur. J. Biochem. 222, 919-925]. Amino acid sequences of seven trypsin fragments from the 97000-M(r) BSP-binding protein were determined. A gene encoding a protein encompassing all seven peptide sequences was identified from chromosomal DNA isolated from S. aureus strain O24. This gene encodes a protein with 1171 amino acids, called BSP-binding protein (Bbp), which displays similarity to recently described proteins of the Sdr family from S. aureus. SdrC, SdrD and SdrE encode putative cell-surface proteins with no described ligand specificity. Bbp also shows similarity to a fibrinogen-binding protein from S. epidermidis called Fbe. A serine-aspartic acid repeat sequence was found close to the cell-wall-anchoring Leu-Pro-Xaa-Thr-Gly sequence in the C-terminal end of the protein. Escherichia coli cells were transformed with an expression vector containing a major part of the bbp gene fused to the gene for glutathione S-transferase. The affinity-purified fusion protein bound radiolabelled native BSP, and inhibited the binding of radiolabelled BSP to staphylococcal cells. Serum from patients suffering from bone and joint infection contained antibodies that reacted with the fusion protein of the BSP-binding protein, indicating that the protein is expressed during an infection and is immunogenic. The S. aureus Bbp protein may be important in the localization of bacteria to bone tissue, and thus might be of relevance in the pathogenicity of osteomyelitis.

Amino Acid Sequence↗
PubMed1998

Virulence factors of Staphylococcus aureus strains causing infective endocarditis--a comparison with strains from skin infections.

The objective was to study potential bacterial virulence factors in S. aureus endocarditis. S. aureus strains isolated from patients with well-classified episodes of infective endocarditis (IE) (n=26) were compared with control S. aureus strains from consecutive patients with skin infections (n=30). The potential virulence factors studied were Staphylococcal enterotoxin A-D (SEA, SEB, SEC, SED) and toxic shock syndrome toxin-1 (TSST-1) production and binding capacity to the extracellular matrix proteins: fibronectin, collagen type I, collagen type II and bone sialoprotein (BSP). None of the potential virulence factors studied was more prevalent among the IE strains. BSP binding was more often found in the control group with skin infections. Endocarditis patients with previous damage of the heart valves were more often infected by strains not producing any enterotoxin. No correlation was found between the potential bacterial virulence factors studied and IE. Concerning the toxins known to act as superantigens (SEA-E and TSST-1), the tendencies in this and other studies indicate that a larger study group might identify them as pathogenic factors in a subgroup of staphylococcal endocarditis.

Adolescent↗
PubMed1997

Staphylococcus aureus causing osteomyelitis binds to a nonapeptide sequence in bone sialoprotein.

Bone sialoprotein is a glycoprotein of the bone and dentine extracellular matrix. This protein consists of 320 amino acids, of which 25% are glutamic and aspartic acid residues. Sialic acid, containing oligosaccharides and tyrosine sulphate residues, supplies additional polyanionic properties. Staphylococcal cells, isolated from patients suffering from infection of bone tissue, bind the bone-derived sialoprotein, an interaction which is specifically inhibited by the recombinant bone sialoprotein core protein. We have previously shown that the 150 N-terminal amino acid residues of bone sialoprotein are responsible for the binding to staphylococcal cells. By using recombinant deleted variants of bone sialoprotein and synthetic peptides, we have now localized the staphylococcal binding site to less than 10 residues within the N-terminal part of the protein.

Amino Acid Sequence↗
PubMed1997

The role of staphylococcal polysaccharide microcapsule expression in septicemia and septic arthritis.

Staphylococcus aureus arthritis is a rapidly progressive and highly erosive disease of the joints in which both host and bacterial factors are of pathogenic importance. One potential bacterial virulence factor is the ability to express a polysaccharide capsule (CP). Among 11 reported capsular serotypes, CP type 5 (CP5) and CP8 comprise 80 to 85% of all clinical blood isolates. The aim of this study was to assess the role of CP5 as a virulence factor in staphylococcal septicemia and septic arthritis with a recently established murine model of hematogenously spread S. aureus arthritis. NMRI mice were inoculated intravenously with S. aureus strains isogenic for expression of CP5, and clinical, bacteriological, serological, and histopathological progression of disease was studied. Inoculation of 7 x 10(6) CFU of S. aureus per mouse induced 55% mortality in the group inoculated with the CP-expressing bacteria, compared to 18% in the group inoculated with CP- mutants. A lower dose of inoculum (3 x 10[6] per mouse) did not give rise to mortality in mice inoculated with CP mutant strains, whereas 18% of the mice inoculated with the CP5-expressing S. aureus died. Importantly, mice inoculated with S. aureus expressing CP5 had a significantly higher frequency of arthritis and a more severe form of the disease. In vitro assays suggested that macrophages were not able to phagocytize CP5+ staphylococci as efficiently as they were CP5- strains. In addition, once phagocytized, CP5+ bacteria were less efficiently killed than CP- mutants. In summary, CP5 leads to a higher frequency of arthritis and a more severe course of the disease. This seems to be related to the effects of the downregulatory properties of CP on the ingestion and intracellular killing capacity of phagocytes. Our results clearly indicate that the expression of CP5 is a determinant of the virulence of S. aureus in arthritis and septicemia.

Animals↗
PubMed1996

Role of the staphylococcal accessory gene regulator (sar) in septic arthritis.

Staphylococcus aureus arthritis is a highly erosive disease in which both host and bacterial factors are of importance for its induction and progression. At the transcriptional level, three known loci act in regulating production of exoproteins and expression of cell wall structures. The aim of our study was to assess the role of the sar locus as a virulence determinant in the pathogenesis of septic arthritis. A recently established murine model of hematogenously spread S. aureus arthritis was employed. S. aureus strains, isogenic for the sar locus, were inoculated intravenously into NMRI mice, and the clinical, bacteriological, serological, and histopathological progression of the disease was studied. Within 1 week after inoculation of bacteria, the frequency of arthritis was 79% in the group of mice inoculated with the sar+ strain, whereas the corresponding frequency in sar mutants was 21% (P < 0.01). Mice inoculated with the sar+ staphylococcal strain exhibited a more pronounced T- and B-lymphocyte activation than those inoculated with the sar mutant, evidenced by splenomegaly, polyclonal B-cell activation, and high serum levels of interleukin 6 and gamma interferon. Also, infection with sar+ staphylococci induced a pronounced weight loss. To assess the relationship between clinical signs and spread of bacteria, we analyzed the homing pattern and persistence of S. aureus in host tissues. Kidneys and joints from sar+-inoculated subjects displayed a higher degree of bacterial persistence than other organs. Our results suggest that molecules controlled by the sar locus are important virulence determinants in the induction and progression of septic arthritis.

Animals↗
PubMed1994

Purification of a bone sialoprotein-binding protein from Staphylococcus aureus.

Bone sialoprotein (BSP) is selectively bound by Staphylococcus aureus cells isolated from patients suffering from infections of bone and joint tissues [Rydén C., Maxe, I., Franzén, A., Ljungh, A., Heinegård, D. & Rubin, K. (1987) Lancet II, 515]. We now report on the purification of a cell-wall protein from Staphylococcus aureus, strain O24, that possesses affinity for bone sialoprotein. Staphylococcal cell-wall components with capacity to inhibit binding of 125I-labeled BSP to staphylococcal cells were solubilized with LiCl (1.0 M, pH 5.0). Preparative SDS/PAGE and protein-overlay experiments revealed that inhibitory activity present in LiCl extracts resided in a fraction of polypeptides with M(r) 75,000-110,000. Staphylococcal proteins solubilized with LiCl were chromatographed on a Mono-Q anion-exchange column. Inhibitory activity was eluted at 0.6-0.8 M NaCl and could be further purified by affinity chromatography on BSP-Sepharose. Elution of the affinity matrix with 0.1 M glycine, pH 3.0, specifically eluted inhibitory activity. Analysis by SDS/PAGE revealed a single M(r) 97,000 polypeptide in the eluate. The purified M(r) 97,000 protein bound BSP in protein-overlay experiments. LiCl extracts from S. aureus, strain E514 or Staphylococcus epidermidis, strain 7686, both lacking the capacity to bind BSP did not contain the M9r) 97,000 protein. Our data demonstrate the presence of a S. aureus cell-surface BSP-binding protein. This protein could be involved in bacterial tropism in osteomyelitis.

Bacterial Proteins↗
PubMed1994

The Staphylococcus aureus collagen adhesin is a virulence determinant in experimental septic arthritis.

The importance of a collagen-binding adhesin in the pathogenesis of septic arthritis has been examined by comparing the virulence of two sets of Staphylococcus aureus mutants in an animal model. Collagen adhesin-negative mutant PH100 was constructed by replacing the chromosomal collagen adhesin gene (cna) in a clinical strain, Phillips, with an inactivated copy of the gene. Collagen adhesin-positive mutant S. aureus CYL574 was generated by introducing the cna gene into CYL316, a strain that normally lacks the cna gene. Biochemical, immunological, and functional analyses of the generated mutants and their respective parent strains showed that binding of 125I-labeled collagen, expression of an immunoreactive collagen adhesin, and bacterial adherence to cartilage were directly correlated with the presence of a functional cna gene. Greater than 70% of the mice injected with the Cna+ strains developed clinical signs of arthritis, whereas less than 27% of the animals injected with Cna- strains showed symptoms of disease. Furthermore, mice injected with the Cna+ strain Phillips had remarkably elevated levels of immunoglobulin G1 and interleukin-6 compared with mice injected with the Cna- mutant PH100. Taken together, these results demonstrate that collagen adhesin plays an important role in the pathogenesis of septic arthritis induced by S. aureus.

Adhesins, Bacterial↗
PubMed1994

Immunopathological features of rat Staphylococcus aureus arthritis.

Staphylococcus aureus is the most common bacterial species found in nongonococcal bacterial arthritis in humans. We present the first description, to our knowledge, of an outbreak of spontaneous staphylococcal arthritis in a rat colony. In a group of 10 rats, 9 displayed arthritis. Clinically, the most obvious findings were arthritis of one or both hindpaws and malaise. Bacteriophage typing showed the common phage type 85 in isolates recovered from the joints, blood, and bedding of rats and from the nose and cheeks of one person from the staff of the animal facility. The S. aureus strain proved to produce staphylococcal enterotoxin A and exhibited strong binding to collagen types I and II and bone sialoprotein, which are potentially important virulence factors. When the recovered S. aureus strain was injected intravenously into healthy rats, severe septic arthritis was induced in almost all of the animals. The arthritic lesions were characterized by infiltration of phagocytic cells and T lymphocytes into the synovium. Many of the synovial cells strongly expressed major histocompatibility complex class II molecules. Increased levels of interleukin 6 in serum as well as a prominent polyclonal B-cell activation were noted throughout the disease course. Pretreatment of S. aureus-injected rats in vivo with an antibody to the alpha beta T-cell receptor significantly decreased the severity of the arthritis. Our results indicate that alpha beta + T lymphocytes contribute to an erosive and persistent course of S. aureus arthritis.

Animals↗
PubMed1993

Identification of a Staphylococcus aureus extracellular matrix-binding protein with broad specificity.

A staphylococal surface protein capable of binding several extracellular matrix glycoproteins was purified as a result of our attempts to identify a receptor(s) for bone sialoprotein (BSP) on Staphylococcus aureus cells. Proteins from different staphylococcal strains were solubilized in sodium lauryl sulfate, separated by polyacrylamide gel electrophoresis, blotted onto Immobilon P membranes, and probed with 125I-BSP. Several bacterial proteins bound the radiolabeled ligand, and various strains expressed different repertoirs of BSP-binding proteins. Major BSP-binding proteins with apparent M(r)s of 72,000 or 60,000 were present on most strains, and these proteins were further studied. The 72- and 60-kDa proteins were preferentially expressed when bacteria were cultured in Luria broth compared with when they were cultured on tryptic soy broth, and the abundance of the proteins could be correlated to an increased 125I-BSP binding. Both the 72-kDa and the 60-kDa proteins were solubilized by extraction of cells with 1 M LiCl and were purified by cation-exchange chromatography. Amino acid composition analysis of the purified 72-kDa protein indicated a high content of lysine (11.9%) and hydrophobic amino acids (28.0% combined). In Western ligand blotting (immunoblotting) experiments, the 72-kDa protein bound not only BSP but also radiolabeled fibronectin, fibrinogen, vitronectin, thrombospondin, and, to some extent, collagen. Addition of the purified 60-kDa protein to S. aureus cells did not inhibit binding of the different ligands but in some cases resulted in an augmentation of the binding of 125I-ligand. Purified 60-kDa protein could hemagglutinate sheep erythrocytes at a concentration of 61 micrograms/ml. The agglutination reaction was inhibited by high concentrations of fucose, mannose, or melibiose. These data suggest that the purified proteins may serve as bacterial receptors with broad specificity for matrix glycoproteins and that the proteins may act as carbohydrate-binding proteins.

Agglutinins↗
PubMed1993

The accessory gene regulator (agr) controls Staphylococcus aureus virulence in a murine arthritis model.

We have studied the role of the accessory gene regulator (agr) of Staphylococcus aureus as a virulence determinant in the pathogenesis of septic arthritis. At least 15 genes coding for potential virulence factors in Staphylococcus aureus are regulated by a putative multicomponent signal transduction system encoded by the agr/hld locus. agr and hld mutants show a decreased synthesis of extracellular toxins and enzymes, such as alpha-, beta-, and delta-hemolysin, leucocidin, lipase, hyaluronate lyase, and proteases, and at the same time an increased synthesis of coagulase and protein A as compared with the wild-type counterpart. We have used a recently described murine model of S. aureus-induced arthritis to study the virulence of S. aureus 8325-4 and two agr/hld mutants derived from it. Sixty percent of the mice injected with the wild-type strain developed arthritis, whereas agrA and hld mutants displayed joint involvement in only 10 and 30%, respectively. In addition, 40% of the mice inoculated with the wild-type strain displayed an erosive arthropathy; such changes were not detectable at all in mice inoculated with the agrA mutant. Serum levels of interleukin-6, a potent B-cell differentiation factor, were significantly higher (P < 0.001) in the mice inoculated with the wild-type strain than in those inoculated with the agrA mutant counterpart. Overall, our results suggest that the agr system of S. aureus is an important virulence determinant in the induction and progression of septic arthritis in mice.

Animals↗
PubMed1991

Experimental Staphylococcus aureus arthritis in mice.

Staphylococcus aureus arthritis is usually caused by bacteremia and is highly destructive. Controlled studies on septic arthritis in humans are difficult to perform, because the time of onset of the infection is unknown. Animal models of bacterial arthritis make it possible to control important variables in experimental studies. We present a mouse model of S. aureus arthritis in which the intravenous administration of 10(7) cells of S. aureus LS-1 induced arthritis or osteitis or both within 3 weeks in 80 to 90% of the mice. Signs of arthritis emerged within the first few days after the injection. An interesting finding was that the S. aureus strain used in this study binds bone sialoprotein, a glycoprotein known to be specifically localized to bone tissue. This new model of S. aureus arthritis enables the study of the kinetics of joint destruction and the host-bacterium relationship as well as therapeutical approaches to septic arthritis and osteomyelitis.

Animals↗
PubMed1990

Detection of Staphylococcus aureus infection by enzyme-linked immunosorbent assay and immunoblotting, using high molecular weight staphylococcal proteins.

Two high molecular weight staphylococcal proteins, fibronectin-binding protein and a Mr 200,000 protein, were investigated as antigens for serodiagnosis of staphylococcal infections. Sera from patients with staphylococcal infections and from controls were subjected to immunoblot analysis with staphylococcal lysate proteins to identify staphylococcal antigens to which patients with staphylococcal infections specifically exhibited antibodies. One such protein was found in the Mr 200,000 region. This protein was purified and used as antigen in ELISA and compared with other antigens, namely fibronectin-binding protein(s) (FNBP, Mr 185,000), alpha-toxin and teichoic acid. Sera from patients with staphylococcal infections contained antibodies to the high molecular weight proteins in higher titers than sera from patients with non-staphylococcal infections or healthy subjects. Based on their amino-acid compositions and different abilities to bind fibronectin it was concluded that the Mr 200,000 protein and FNBP were not identical.

Adolescent↗
PubMed1989

Specific binding of bone sialoprotein to Staphylococcus aureus isolated from patients with osteomyelitis.

Bone sialoprotein is selectively bound by Staphylococcus aureus cells isolated from patients suffering from infections of bone tissue [Rydén, C., Maxe, I., Franzén, A., Ljungh, A., Heinegård, D. & Rubin, K. (1987) Lancet II, 514]. In the present communication the binding of bone sialoprotein to staphylococcal cells is characterized in more detail. 125I-Labelled bone sialoprotein bound to suspended staphylococcal cells in a time-dependent, saturable and reversible manner. Binding was inhibited by unlabelled bone sialoprotein and by an amino-terminal CNBr fragment of bone sialoprotein that did not contain the eukaryotic cell-binding site. Binding was furthermore inhibited by lysates obtained from Escherichia coli lysogens carrying a lambda gt11 phage-encoding bone sialoprotein. In contrast, binding was not inhibited by a bacterial lysate from an osteopontin lambda gt11 lysogen, nor by N-linked oligosaccharide isolated from bone sialoprotein or by proteoglycan from rat chondrosarcoma containing clustered O-linked oligosaccharides of the same structure as those of bone sialoprotein. These results indicate that the major staphylococcal-binding site resides in the bone sialoprotein core protein and not in the carbohydrate side chains. No inhibition of bone sialoprotein binding could be detected for whole human serum or purified plasma proteins such as fibronectin, fibrinogen and IgG. Likewise, staphylococcal protein A or rat collagen type I did not inhibit the binding of bone sialoprotein. The latter results indicate that the binding site for bone sialoprotein on staphylococcal cells was not any of the hitherto described staphylococcal cell-surface proteins. Binding data indicated an average of 1000 bone-sialoprotein-binding sites/bacterial cell.

Animals↗
PubMed1986

Specific attachment of Staphylococcus aureus to immobilized fibronectin.

Staphylococcus aureus cells have been shown to possess surface-associated proteins with affinity for soluble fibronectin. We have investigated the ability of these surface proteins to mediate attachment to immobilized fibronectin and collagen. Attachment was quantified by determination of bacterial ATP in a bioluminescence assay. The ability to attach to fibronectin- or collagen-coated plastic surfaces was investigated for four S. aureus strains: Cowan 1, Newman, SA113(83A), and Wood 46. Cells from the different strains varied in their attachment properties, but all cells except those of strain Wood 46 attached readily to substrates coated with fibronectin. Only cells from strain Cowan 1 attached reproducibly to collagen-coated substrates in the absence of fibronectin. The attachment of cells from strain SA113(83A) to fibronectin-coated surfaces was shown to be dependent on time, fibronectin concentration, and bacterial growth phase. Soluble fibronectin or NH2-terminal fibronectin fragment (Mr, 29,000) disturbed the attachment to surfaces coated with fibronectin bound to denatured collagen type I. The attachment process to such substrates was also effectively inhibited by preincubating the substrate with fibronectin-binding proteins isolated from S. aureus Newman and SA113 (83A) and purified with affinity chromatography.

Amino Acid Sequence↗
PubMed1983

Binding of fibronectin to Staphylococcus strains.

Fibronectin, a major protein component of plasma and loose connective tissue has previously been shown to bind to several strains of Staphylococcus aureus. We examined a large number of strains of different species of Staphylococcus with respect to their ability to bind fibronectin. The relative numbers of strains defined as fibronectin-binders among the different species were as follows: S. aureus (22 of 23), S. haemolyticus (5 of 5), S. warneri (8 of 11), S. hyicus (5 of 6), S. hominis (13 of 17), S. saprophyticus (11 of 20), S. epidermidis (4 of 7), and S. simulans (8 of 10). Only three species showed a predominance of nonbinders over binders: S. capitis (4 of 14), S. xylosus (0 of 4), and S. cohnii (3 of 11). These data indicate that staphylococcal species isolated from soft tissue infections frequently have the ability to bind fibronectin and suggest that the ability to bind to this protein may contribute to the virulence of coagulase-positive and coagulase-negative staphylococci.

Fibronectins↗