Biomedical subjects

T Wadström

Publications and source records attributed to T Wadström.

At least 19 recordsLinked to original sources

PubMed1992

Surface properties, connective tissue protein binding and Shiga-like toxin production of Escherichia coli isolated from patients with ulcerative colitis.

Escherichia coli strains isolated from intestinal biopsies of patients with ulcerative colitis (n 146), Crohn's disease and colonic polyposis (n 41) were analysed for binding of collagen I, collagen IV, fibronectin and laminin. Strains expressed varying degrees of binding of one or more of the four connective tissue proteins. Only 32 strains did not express binding of any of the proteins. The strains expressed low or moderate cell surface hydrophobicity. There was no correlation between protein binding and expression of cell surface hydrophobicity. E. coli isolated from inflamed rectal mucosa were slightly less negatively charged than strains isolated from healthy intestinal mucosa. Shiga-like toxins I and II were detected in 32 strains from 28 patients. Of these, 5 strains had been isolated from normal or healed tissue. In patients with inflammatory bowel disease, connective tissue proteins are exposed in intestinal ulcerations. Strains expressing binding of one or several of these proteins may have a selective advantage to colonize these lesions.

Adolescent↗

PubMed1992

Vitronectin-binding surface proteins of Staphylococcus aureus.

S. aureus strain ISP 546 was selected (of 55 strains tested) to define optimal conditions for expression of vitronectin binding. High binding was expressed when the strain was grown on blood agar and in Todd-Hewitt broth. Binding was optimal in the 6.0 to 7.2 pH range and was unaffected by divalent cations and ionic strength. Binding was partially inhibited by D-mannose, heparin, types I and IV collagen, fibronectin, fibrinogen and vitronectin, but was not affected by other carbohydrates or glycoproteins tested. Cell surface binding components were extracted with the aid of 1 M LiCl (pH 5.0) from strain ISP 546 grown in Todd Hewitt broth. Vitronectin binding proteins were purified by affinity chromatography on heparin-Sepharose. Fractions inhibiting binding of 125I-labelled vitronectin to strain ISP 546 were eluted by 0.01 M NaOH, dialysed, concentrated and subjected to SDS-PAGE. Silver staining revealed one major band (70 kDa) and two minor bands (34 and 36 kDa).

Binding, Competitive↗

PubMed1992

Binding of laminin, type IV collagen, and vitronectin by Streptococcus pneumoniae.

Forty-three strains of Streptococcus pneumoniae were tested for their ability to bind radiolabelled laminin, collagen types I, II and IV, fibronectin, and vitronectin. Two basement membrane components, laminin and type IV collagen, interacted with many S. pneumoniae strains. All strains bound laminin and 28 (65%) bound collagen type IV. Approximately 60% of the strains bound vitronectin but only a few strains showed low binding of fibronectin and collagen type I and II.

Bacterial Adhesion↗

PubMed1992

Binding of Chlamydia trachomatis serovar L2 to collagen types I and IV, fibronectin, heparan sulphate, laminin and vitronectin.

Chlamydia trachomatis serovar L2 elementary bodies were tested for binding to 125I-labelled components of the extracellular matrix. C. trachomatis bound high levels of collagen type I and heparan sulphate, whereas the binding to collagen type IV, fibronectin, laminin and vitronectin was substantially less. Preliminary characterization showed that chlamydial surface proteins are essential for binding to occur. Our results suggest that a selective affinity for C. trachomatis to a limited number of components of the extracellular matrix may have important implications mediating attachment to host cell surfaces and localization of chlamydiae in other tissues, such as joints.

Bacterial Adhesion↗

PubMed1992

Immunological response to a Staphylococcus aureus fibronectin-binding protein.

A protein (gal-FnBP), constructed by fusion of the genes encoding beta-galactosidase of Escherichia coli and the binding domains of fibronectin-binding protein (FnBP) of Staphylococcus aureus was used. FnBP is a surface protein responsible for attachment of bacteria to extracellular matrix of various host tissues. Gal-FnBP is more stable and can be produced in larger quantities than native FnBP. The binding specificity of this fusion protein was established in a Western blot analysis. Treatment of gal-FnBP with formalin inactivated the binding capacity of the protein but immunogenicity was retained. Immunisation of mice with formalin-treated gal-FnBP resulted in high antibody titres against the fibronectin-binding part of this fusion protein. These antibodies were measured by their ability to block the specific binding of fibronectin to gal-FnBP in a blocking assay. Sera raised against formalin-treated gal-FnBP and non-treated gal-FnBP blocked this binding to 40 and 25% respectively, thereby indicating the usefulness of gal-FnBP as a vaccine component.

Adhesins, Bacterial↗

PubMed1992

Interaction of staphylococcal fibronectin binding protein (FnBP), TSST-1 and alpha-toxin with murine lymphocytes.

The most restrictive factor in the inductive phase of immune response is the contact and adhesion of antigen-presenting cells and responding lymphocytes. We report the in vitro formation of aggregates (clusters) of murine T lymphocytes and dendritic cells (DC) pulsed with highly purified staphylococcal toxins (TSST-1, alpha-toxin) and gene-cloned surface fibronectin binding protein (gal-FnBP). A high percentage of T lymphocytes were involved in clustering with TSST-1-pulsed DC. Lymphocytes of mice infected with Staphylococcus aureus (strain Cowan 1) 21 days before testing, clustered with the same ability as cells of mice infected 3 days before. Dendritic cells pulsed with alpha-toxin formed a moderate number of clusters only when co-cultured with T lymphocytes of mice infected 3 days before the test. FnBP-pulsed DC aggregated strongly with T lymphocytes. This response peaked at 3-4.5 h-cultures and increased again after 24 h. We concluded that at the beginning of co-culture, FnBP amplified the cells' adhesion process on antigen-independent way. This conclusion is supported by the observation that DC pulsed with formalin-modified FnBP (with a 65% decreased ability to bind fibronectin) formed fewer clusters with T-immune cells than dendritic cells pulsed with native, non-treated FnBP.

Animals↗

PubMed1992

Interaction of fibronectin and fibronectin binding protein (FnBP) of Staphylococcus aureus with murine phagocytes and lymphocytes.

In the present study we examined the in vitro and in vivo interactions of a cloned staphylococcal fibronectin binding protein (FnBP) and plasma fibronectin (Fn) with polymorphonuclear cells (PMNs) and macrophages, and how antibodies against FnBP affect the phagocytosis process in vitro. Moreover, the interaction of FnBP and Fn coupled on latex beads as 'artificial bacteria' and 'artificially opsonized bacteria' with murine spleen cells and peritoneal macrophages was tested. The major finding of the present study is that antibodies against the FnBP of Staphylococcus aureus (S. aureus) and low concentration of antibodies recognized two IgG-binding domains of protein A (SpA) are effective in the promotion of phagocytosis in vitro. It was also observed that FnBP has a chemoattractant activity and causes accumulation of PMNs and macrophages in the mouse peritoneal cavity when injected 24 h before irritation of peritoneal exudate. It seems likely that this activity is connected with binding to Fn molecules since formalin inactivation of FnBP (60%) abolished it. In the in vitro phagocytosis assay in the presence of FnBP (in a medium supplemented with serum depleted of Fn), ingestion of bacteria by phagocytes was identical to assay carried out in the presence of BSA. However, addition of plasma fibronectin caused an increased uptake of bacteria by macrophages and to a lesser degree by PMNs. We observed that in a population of normal splenocytes, those cells that effectively bound FnBP- and Fn-coated latex beads were mostly those cells exhibiting macrophage and dendritic morphology. In populations of spleen cells of animal infected with S. aureus, T lymphocytes were also found to bind FnBP- and Fn-coated latex beads. These data suggest that FnBP may have the ability to promote aggregation of immune cells, either directly or by interaction with plasma Fn, which can be helpful in certain cell-cell interactions taking place at the initial stages of specific immune response.

Animals↗

PubMed1992

Vitronectin binding by Helicobacter pylori.

Vitronectin, a serum and extracellular matrix protein involved in immunological reactions, interacts with Helicobacter pylori strains. Of the 20 H. pylori strains tested three strains bound more than 50% of the vitronectin added, five strains bound 25-40%, nine strains bound 10-20% and three strains bound 5-8% vitronectin. Two strains, one with high- and one with low-binding properties, were selected for further characterization of 125I-vitronectin binding. Binding to the urea-activated 125I-labelled vitronectin was fast, saturable and reversible when an excess of unlabelled vitronectin was added to the bacteria with bound 125I-vitronectin. The binding was heat- and protease-sensitive, suggesting that the binding was mediated by bacterial cell-surface proteins. Since components such as fetuin and orosomucoid but not asialofetuin inhibited the binding, sialic-acid specific proteins, related to H. pylori sialic-acid specific haemagglutinins, were probably involved.

Blood Proteins↗

PubMed1992

Binding of heparan sulfate to Staphylococcus aureus.

Heparan sulfate binds to proteins present on the surface of Staphylococcus aureus cells. Binding of 125I-heparan sulfate to S. aureus was time dependent, saturable, and influenced by pH and ionic strength, and cell-bound 125I-heparan sulfate was displaced by unlabelled heparan sulfate or heparin. Other glycosaminoglycans of comparable size (chondroitin sulfate and dermatan sulfate), highly glycosylated glycoprotein (hog gastric mucin), and some anionic polysaccharides (dextran sulfate and RNA) inhibited heparan sulfate binding to various extents. Heat treatment (80 degrees C for 10 min) and treatment of the bacteria with pronase E, proteinase K, pepsin, and chymotrypsin considerably reduced their ability to bind 125I-heparan sulfate, but treatment with trypsin and neuraminidase did not affect binding. Scatchard plot analysis indicated the presence of cell surface components with low affinity (Kd = 3 x 10(-5) M) for heparan sulfate. Cell surface components were released by stirring bacteria with 1 M LiCl at 37 degrees C for 2 h. Proteins of this extract that competitively inhibited binding of 125I-heparan sulfate to S. aureus were isolated by affinity chromatography on heparin-Sepharose. Two proteins having molecular masses of approximately 66 and 60 kDa and the ability to bind 125I-heparan sulfate were obtained. The first 9 amino-terminal amino acid residues of the 66-kDa protein are Asp-Trp-Thr-Gly-Trp-Leu-Ala-Ala-Ala, and the first 4 amino-terminal amino acid residues of the 60-kDa protein are Met-Leu-Val-Thr.

Amino Acid Sequence↗

PubMed1992

Rapid detection of Helicobacter pylori in gastric biopsy material by polymerase chain reaction.

By using primers based on the sequence of a species-specific antigen of Helicobacter pylori (P. O'Toole, S.M. Logan, M. Kostrzynska. T. Wadström, and T.J. Trust, J. Bacteriol. 173:505-513, 1991), a protocol was established for detection of this microorganism in gastric biopsy samples by the polymerase chain reaction (PCR). A single primer pair was used to specifically amplify a 298-bp sequence in a rapid two-step PCR. The primers exhibited the same specificity in PCR as that which we reported for the species-specific gene probe on which they were based. The sensitivity of the method was 20 copies of the target sequence, or 70 bacterial cells, under the lysis conditions used for patient-derived material. When amplification was performed for a saturating number of cycles, visual examination of ethidium bromide-stained gels successfully detected all samples subsequently judged to be positive by Southern hybridization of the gel with a probe specific for the PCR product. The bacterium could be detected in gastric biopsy samples from patients with various gastric diseases, including samples from which the bacterium could not be cultured. Only 9 of 19 patients who tested positive by PCR of gastric biopsy material were positive when a saliva sample was analyzed. Protocols for sample handling which minimized the risk of contamination while maximizing the sensitivity of the reaction were established. The results support a role for PCR in the rapid identification of H. pylori in clinical samples.

Adult↗

PubMed1992

Optimal survival of Helicobacter pylori under various transport conditions.

The ability of clinical isolates and type strains of Helicobacter pylori to survive in Stuart transport medium, isotonic saline solution, and urea-containing isotonic saline was evaluated. The influences of temperature (4, 10, 15, 20, and 30 degrees C) and holding time (6 to 48 h) and the effect of exposure to air on survival were also studied. The recovery rate of H. pylori was highest from Stuart transport medium in comparison with the recoveries from the other transport media tested. We found that at holding temperatures above 15 degrees C the organisms became noncultivable within 6 h or less, while they survived for 2 days or longer at 10 degrees C. The presence of urea at a concentration of 2% (wt/vol) in isotonic saline resulted in the loss of viability of the organisms tested.

Air↗

PubMed1992

Rapid identification of fibronectin, vitronectin, laminin, and collagen cell surface binding proteins on coagulase-negative staphylococci by particle agglutination assays.

Seventeen strains of ten different species of coagulase-negative staphylococci were shown to interact with collagen, laminin, fibronectin, and vitronectin immobilized on latex beads. Different species of coagulase-negative staphylococci have different capacities to agglutinate proteins. Cells of 18 strains of Staphylococcus haemolyticus reacted more strongly than did cells of 18 Staphylococcus epidermidis strains with proteincoated latex beads, although no significant difference in cell surface hydrophobicity or charge could be shown. The cell surface receptors of S. haemolyticus were more heat and protease resistant than were Staphylococcus aureus receptors. Strains of Staphylococcus saprophyticus isolated from urinary tract infections showed a high capacity to adhere to laminin. The ability to agglutinate fibronectin and collagen was common among coagulase-negative staphylococci isolated from other infections; 55% (31 of 56) and 63% (35 of 56) agglutinated fibronectin and/or collagen. S. haemolyticus and S. epidermidis bound to both N-terminal (29-kDa) and C-terminal (120-kDa) fragments of fibronectin.

Bacteriological Techniques↗

PubMed1992

Cell surface proteins of Helicobacter pylori as antigens in an ELISA and a comparison with three commercial ELISA.

Cell surface proteins of Helicobacter pylori were solubilized by extraction with acidic glycine buffer, N-octyl-glucoside, lithium chloride, and distilled water, and by sonication. The preparations were evaluated as antigens in ELISA to detect serum IgG responses in patients and healthy subjects. SDS-PAGE analyses of the preparations from a type strain (NCTC 11637) and of acidic glycine extracts of 4 clinical isolates showed multiple protein bands. The sera were classified as HP+ve and HP-ve by culture of biopsy and immunoblotting. Sera were considered positive for H. pylori if they detected the specific 120kD antigen or 4-5 other bands. 49 sera were HP+ve; the 51 HP-ve sera did not react in immunoblotting. 35/44 sera (80%) that reacted with the 120kD antigen demonstrated high titers in ELISA with all antigen preparations, and the remaining 9(20%) sera gave discordant results. 4/5 HP+ve sera that did not react with the 120kD antigen, demonstrated high ELISA titers with all 5 antigen preparations. Glycine extracts of 3 isolates did not exhibit the 120kD protein, but were equally sensitive in ELISA. The role of 120kD antigen in our ELISA was not clear. Immunoblotting demonstrated that the 5 antigen preparations share similar antigenic components. All preparations were similarly high in sensitivity and specificity, indicating that surface antigens could be satisfactorily used in our ELISA. Our ELISA using the glycine extract was compared with commercial H. pylori ELISAs developed by Bio-Rad Laboratories, USA (GAP ELISA), Roche, Switzerland (EIA 2G), and Whittaker Bioproducts, USA (Pyloristat).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Bacterial↗

PubMed1992

Comparative studies on binding of vitronectin and fibronectin to groups A and C streptococci.

Binding of 125I-labelled fibronectin and vitronectin to streptococci of group A (S. pyogenes), group B (S. agalactiae) and group C (S. dysgalactiae and S. zooepidemicus) isolated from various human infections and bovine mastitis, and S. uberis bovine isolates, was studied. Binding of vitronectin and fibronectin was common among both human groups A and C, and bovine group C streptococci. S. agalactiae strains of human and bovine origin as well as S. uberis bovine isolates bound low levels of both proteins. The binding of radiolabelled fibronectin and vitronectin to selected groups A and C streptococcal strains was specific, time-dependent and occurred with both live and heat-killed (80 degrees C for 15 min) cells. Binding declined rapidly after treatment of cells with trypsin or proteinase K, while pepsin digestion at pH 5.5 affected vitronectin but not fibronectin binding.

Culture Media↗

PubMed1992

Haemagglutination patterns of Helicobacter pylori. Frequency of sialic acid-specific and non-sialic acid-specific haemagglutinins.

Thirty-two Helicobacter pylori strains were screened for haemagglutination (HA) activity with erythrocytes of 11 different animal species. Twenty-three strains (72%) that agglutinated human erythrocytes exhibited a broad-spectrum HA profile. Human, guinea pig and bovine erythrocytes high in sialoglycoconjugates were strongly agglutinated by most strains. Except for two, seven strains (22%) that did not agglutinate human erythrocytes exhibited a narrow-spectrum HA profile, commonly not inhibitable by sialoglycoconjugates or N-acetylneuraminlactose (NANLac). Strains were classified into three major HA classes. HA of 10 strains (31%) in class I was inhibited by different combinations of NANLac, orosomucoid or fetuin, but not by asialofetuin, suggesting the presence of sialic acid-specific HAs probably recognizing NeuAc alpha-(2-3)- Gal isomer. Twelve strains (38%) in class II exhibited a different receptor specificity binding to different combinations of NANLac, orosomucoid and fetuin, as well as asialofetuin. No inhibition was observed with 10 strains (31%) in class III; thus, this receptor seems different from both the other classes. Of 21 strains (66%) in classes I and II, HA of 11 strains (34%) was inhibited with NANLac, 14 strains (44%) with orosomucoid and 15 strains (47%) with fetuin. The great heterogeneity observed in HA patterns indicates that the HAs of different strains may recognize a heterogeneous class of sialoglycoconjugates on the erythrocyte membrane.

Animals↗

PubMed1992

Lactoferrin binding properties of Vibrio cholerae.

The lactoferrin binding properties of Vibrio cholerae, a non-invasive pathogen were investigated. Screening of fifty V. cholerae strains of different serogroups and serotypes, showed that 10% of the V. cholerae strains bound to 125I-labelled lactoferrin, and 40% of the 125I-labelled lactoferrin bound to V. cholerae strain 623 could be displaced by unlabelled lactoferrin. Other iron-binding glycoproteins and ferroproteins like ferritin, transferrin, haemoglobin, and myoglobin inhibited the binding of 125I-lactoferrin to a lesser degree. Monosaccharides (GalNac, Man, Gal, and Fuc), and other glycoproteins such as fetuin and orosomucoid also inhibited the binding to a lesser extent. V. cholerae 623 showed a cell surface associated-proteolytic activity which cleaved off the cell-bound 125I-labelled lactoferrin. The generation of cryptotopes on the V. cholerae cell surface by proteolytic digestion favoured the binding of ferritin, transferrin, haemoglobin, and haemin, as well as Congo red, to cells of V. cholerae 623.

Animals↗

PubMed1992

Helicobacter pylori and atrophic gastritis.

Sixty-four consecutive patients which on upper gastrointestinal endoscopy had endoscopic signs of atrophic body gastritis were investigated with standard histology examinations of gastric biopsies, serology and/or culture for Helicobacter pylori and with standard blood chemistry profile. A histologic diagnosis of atrophy could be made in only 27 of the 64 patients (42%). Of these 27 patients, 5 had the pernicious anaemia (PA) type (19%), 22 had not (81%). Past and/or present H. pylori infection was found in 16/22 non-PA patients (73%) but in none of the PA patients (p = 0.00572). The present study thus confirms earlier findings that non-PA type atrophic body gastritis is more common than the PA type and suggests that, as opposed to PA-type atrophy, it is related to H. pylori infection.

Adult↗

PubMed1991

New lectins and other putative adhesins in Aeromonas hydrophila.

The ability of strains of Aeromonas hydrophila to bind 125I-labelled collagen types I and IV, fibronectin, laminin, lactoferrin, and immobilized mucins and orosomucoid on latex beads was found to be a property common to all the isolated strains. The binding was specific, was inhibited by homologous unlabelled glycoproteins, and was protease sensitive. The nature of the binding is discussed.

Aeromonas↗