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Biomedical subjects

F Espersen

Publications and source records attributed to F Espersen.

At least 127 records · Page 7Linked to original sources
PubMed1989

Staphylococcus aureus bacteraemia in children below the age of one year. A review of 407 cases.

The bacteriology, epidemiology, infection types and mortality were reviewed in 407 cases of Staphylococcus aureus bacteraemia in the period 1967-1984 in children less than one year old. The number of bacteraemia cases in this age group increased in the seventies, but only 4% of the bacteraemias seemed to be due to epidemic spreading. Neonates might be at higher risk for S. aureus bacteraemia than older children less than one year old, and nearly all infections in the neonatal period were hospital-acquired. The mortality was 24%, and did not correlate with type of infection, but in neonates it correlated with low birthweight.

Cross Infection↗
PubMed1989

Purification, characterization, and immunological cross-reactivity of alginates produced by mucoid Pseudomonas aeruginosa from patients with cystic fibrosis.

Alginates from nine mucoid Pseudomonas aeruginosa isolates from patients with cystic fibrosis were purified by repeated ethanol precipitation, nuclease digestion, anion-exchange chromatography, dialysis, and lyophilization. Uronic acid constituted 72% of the dry weight when mannuronolactone was used as the internal standard in the carbazole-borate assay for uronic acids. The average degree of acetylation was 16%, and the ratio of mannuronic acid to gluluronic acid was 4.7. No homopolymeric blocks of guluronic acid were found when analyzed by nuclear magnetic resonance spectroscopy. Contaminating proteins were denatured by heating, and during purification the content of protein relative to alginate fell from 566 to 0.9%. The content of lipopolysaccharide was 0.012%. No immunological or biological activity was attributable to the protein or lipopolysaccharide content as estimated by immunoblotting, enzyme-linked immunosorbent assay (ELISA), and a neutrophil chemotaxis assay. Rabbits were hyperimmunized with P. aeruginosa alginates and alginate from the seaweed Laminaria hyperborea, and an ELISA that detected alginate-specific antibodies was developed. Antibodies to P. aeruginosa alginate were detected by ELISA in 1:4,000 dilutions of serum from patients with cystic fibrosis with chronic P. aeruginosa lung infection. The serological cross-reactions between serum from the nine patients with cystic fibrosis and the corresponding P. aeruginosa alginates were investigated and showed considerable heterogeneity. This finding indicates that P. aeruginosa alginate from more than one P. aeruginosa strain should be used in serological tests. There was no serological cross-reactivity between P. aeruginosa and Laminaria hyperborea alginate in either rabbits or patients with cystic fibrosis.

Alginates↗
PubMed1988

Excretion of urinary collagen metabolites correlates to severity of pulmonary disease in cystic fibrosis.

The urinary excretion of collagen metabolites (hydroxylysine, hydroxyproline and proline) was significantly increased in 10 patients with cystic fibrosis and chronic broncho-pulmonary Pseudomonas aeruginosa infection as compared with 14 age matched controls. The increase was significantly correlated to impaired pulmonary function (FVC and FEV1). The results indicate that urinary collagen metabolites reflect degradation of lung connective tissue and may be an indicator of the severity of pulmonary disease in cystic fibrosis. Parts of the excreted hydroxyproline may be degradation products of elastin.

Adolescent↗
PubMed1988

Detection of staphylococcal toxic shock syndrome toxin 1 by a latex agglutination kit.

A commercial reversed passive latex agglutination kit (Oxoid), that detects toxic shock syndrome toxin 1 (TSST-1), was evaluated for its ability to support the clinical diagnosis of toxic shock syndrome (TSS) by detecting the presence of TSST-1 producing Staphylococcus aureus. 15/16 isolates from patients with TSS were positive, while 4/50 vaginal isolates from patients without TSS were positive. The kit can be recommended as it was easy to handle, and gave results identical with those obtained by a standard assay.

Bacterial Toxins↗
PubMed1988

Crossed immuno-electrophoretic analysis of Yersinia enterocolitica serotype 0:3 antigens.

By means of quantitative immuno-electrophoretic methods, 81 different antigens were demonstrated in sonicated preparations of Yersinia enterocolitica, serogroup 0:3, using corresponding rabbit antiserum. Only chromosomally-encoded antigens were demonstrated in this system. Thirteen antigens were located on the bacterial surface, as demonstrated after absorption of rabbit antiserum with whole, killed bacteria. Five antigens resisted boiling. Antigen No. 71 was identified as an important part of the lipopolysaccharide, and antigen No. 6 as the "common antigen" of Pseudomonas aeruginosa. Binding activities to concanavalin A (indicating the presence of carbohydrates), to Limulus amoebocyte lysate and to polymyxin B (indicating the presence of possible endotoxin activity) were demonstrated for five, nine, and seven antigens, respectively. These observations, together with the presence of corresponding antibodies in pre-immune rabbit sera, as well as cross-reactivity with other Gram-negative bacteria, indicate the biological importance of several of these antigens.

Antibodies, Bacterial↗
PubMed1988

Cross-reactions between Yersinia enterocolitica serogroup 0:3 and other serogroups of the same species, as well as thirty-four other bacterial species.

Cross-reactions between antigens from Yersinia enterocolitica serogroup 0:3 and 5 other members of the same species as well as 34 other bacterial species were studied by means of quantitative immunoelectrophoretic methods. A sonicated Y. enterocolitica antigen preparation and corresponding purified rabbit antibodies were used in a reference system that presented 58 regularly visible immunoprecipitates. One antigen was identified as specific for the Y. enterocolitica 0:3 serogroup and two antigens for the species Y. enterocolitica. Y. enterocolitica antigens cross-reacted widely with antigens from other Enterobacteriaceae, but only a few cross-reactions were registered with Gram-negative bacteria outside the Enterobacteriaceae. A partial cross-reaction between all Gram-positive bacteria included in our study and two Y. enterocolitica antigens was demonstrated.

Antigens, Bacterial↗
PubMed1987

Histamine release induced by bacteria. A new mechanism in asthma?

Bacteria release histamine from human basophil leukocytes and mast cells. The release can be caused by an immunological (IgE-dependent) mechanism, but mostly we found a non-immunological (lectin-mediated) mechanism which indicates that mediator release triggered by bacteria can occur without the person being sensitized to the micro-organism in question. Both bacteria and bacterial products such as endotoxins potentiate basophil histamine release caused by allergens in allergic patients or by bacteria in persons sensitized to the micro-organisms. It is therefore tempting to speculate that bacteria and their products might be of importance for asthma by their capacity to release histamine and to potentiate mediator release.

Asthma↗
PubMed1987

Bacteria and their products peptidoglycan and teichoic acid potentiate antigen-induced histamine release in allergic patients.

Histamine release was examined in leukocyte suspensions from patients allergic to grass pollen, mite or cat dander or to bacteria (antigen). When the cells were challenged with specific antigen plus bacteria to which the person was not sensitized, these bacteria were found to potentiate the allergic histamine release. The potentiating effect by bacteria might be due to the bacterial cell wall components, peptidoglycan and teichoic acid, which mimic the effect of bacteria.

Antigens, Bacterial↗
PubMed1987

Antibiotic treatment of Staphylococcus aureus endocarditis. A review of 119 cases.

Clinical and bacteriological information of Staphylococcus aureus endocarditis was reviewed in 119 cases from all over Denmark. Overall mortality was 71%. Survival correlated with antistaphylococcal treatment, short duration from onset of infection to start of treatment, and long duration of treatment. In spite of relevant treatment, mortality was significantly lower in cases infected with penicillin-susceptible strains than when penicillin-resistant strains were isolated. There were no differences in the effect of various anti-staphylococcal treatment regimens; in particular, there were no differences in mortality with regard to beta-lactam antibiotics alone as compared to beta-lactam antibiotics in combination with aminoglycosides. However, embolic manifestations occurred more often after start of treatment with combination therapy than with beta-lactam antibiotics alone.

Anti-Bacterial Agents↗
PubMed1987

Staphylococcus aureus bacteremia in patients with hematological malignancies and/or agranulocytosis.

A total of 6,253 cases of Staphylococcus aureus bacteremia, including 274 (4.4%) endocarditis cases, were registered in Denmark in the period 1975-1984. Patients with hematological malignancies and/or agranulocytosis accounted for 479 of the bacteremia cases. The incidence of endocarditis in this group of patients was only 0.4% as compared to 4.7% in other patients with staphylococcal bacteremia (p less than 0.01). The lower incidence of endocarditis complicating bacteremia in these patients may justify a shorter course of therapy than usually recommended for suspected endocarditis. Patients with hematological malignancies and other patients with agranulocytosis had a higher mortality (49 and 46%, respectively) than other patients with S. aureus bacteremia (33%). The highest mortality was found in patients with multiple myeloma (71%, p less than 0.01), the lowest in patients with acute lymphocytic leukemia (28%, p less than 0.01). The higher mortality in these patients may indicate that empiric antibiotic regimens in granulocytopenic patients should include a specific anti-staphylococcal agent.

Aged↗
PubMed1987

Antibody response to whole cells and teichoic acid of Staphylococcus aureus strain E 1369 in human sera.

A whole cell Staphylococcus aureus enzyme-linked immunosorbent assay (ELISA) using the protein A-deficient strain E 1369 as antigen was compared to an ELISA with cell-wall teichoic acid, extracted from the same strain, as antigen for the detection of IgG antibodies against S. aureus in human sera. A total of 178 serum samples from 119 patients with S. aureus endocarditis, complicated and uncomplicated septicaemia, non-S. aureus endocarditis and septicaemia were investigated together with sera from 155 healthy controls. The sensitivity in diagnosing S. aureus endocarditis was better for the whole cell-ELISA (83%) as compared to the teichoic acid-ELISA (61%), and the same was true for complicated septicaemia (41% vs 29%). The whole cell ELISA was also more specific for S. aureus infections with only 3.6% false positive test values compared to 7.1% for the teichoic acid-ELISA. The differences were however, not statistically significant. None of the assays were able to distinguish between complicated and uncomplicated S. aureus septicaemia.

Antigens, Bacterial↗
PubMed1987

Diagnosis of chronic Pseudomonas aeruginosa infection in cystic fibrosis by enzyme-linked immunosorbent assay.

An easily applicable test for diagnosis of chronic Pseudomonas aeruginosa infection in cystic fibrosis by enzyme-linked immunosorbent assay (ELISA) for determination of serum immunoglobulin G to P. aeruginosa was developed. Soluble antigens obtained by ultrasonication of P. aeruginosa, serotypes O:1 to O:17, were used as antigens immobilized to polystyrene microtiter plates. The intraplate, plate-to-plate, and day-to-day variations were 14, 19, and 20%, respectively. Plates coated with the antigens could be stored for at least 64 days at +4 and +22 degrees C without any significant change in activity. Normal values were determined in sera from 164 controls (100 children and 64 adults). The sensitivity and specificity of the ELISA was determined by using serum samples from 243 cystic fibrosis patients and were compared to results with crossed immunoelectrophoresis (CIE). The ELISA could diagnose chronic P. aeruginosa infection with a diagnostic sensitivity of 93% and specificity of 92%. The sensitivity and specificity for the diagnosis of the early stages of chronic P. aeruginosa infection by a single sample were 90 and 100%, respectively, and by using an increased antibody response in paired samples, the sensitivity was 93% and specificity was 87%. There was a statistically significant correlation between antibody levels obtained by ELISA and those obtained by CIE. The sensitivity and specificity of the ELISA were equal to those of CIE, and because of its simplicity, the ELISA is recommended as a routine test in patients with cystic fibrosis.

Adolescent↗
PubMed1987

Solid-phase radioimmunoassay for IgG antibodies to Staphylococcus epidermidis. Use in serious coagulase-negative staphylococcal infections.

A radioimmunoassay (RIA) for human IgG antibodies to Staphylococcus epidermidis was compared with an agar-gel-diffusion assay in patients with a variety of infections. The RIA was sensitive and reproducible and discriminated between endocarditis and uncomplicated bacteremias due to coagulase-negative staphylococci. Anti-S epidermidis antibodies by RIA were elevated in 16 (89%) of 18 patients with coagulase-negative staphylococcal endocarditis but in none of 28 patients with uncomplicated bacteremia (n = 18) or with blood culture contaminated with these organisms (n = 10). Cross-reacting IgG antibodies to S epidermidis antigens were also detected by RIA in 13 (76%) of 17 patients with Staphylococcus aureus endocarditis but in none of 17 patients with nonvalvular S aureus bacteremias and in none of 25 patients with endocarditis or bacteremia caused by other pathogens. Agar-gel-diffusion assay was less sensitive than RIA for detecting coagulase-negative staphylococcal endocarditis, being positive in nine (50%) of 18 such patients. This RIA may be useful in distinguishing patients with endocarditis from those with nonvalvular staphylococcemias or blood culture contamination.

Antibodies, Bacterial↗
PubMed1987

Interactions between human plasma proteins and cell wall components of Staphylococcus aureus.

Staphylococcus aureus has surface structures with affinity to human IgG, fibrinogen, and fibronectin. Besides the binding of the Fc-terminal part of IgG from a range of mammalian species, S. aureus protein A binds some IgM, IgA, and IgE molecules. Furthermore, it seems also able to bind immunoglobulins via their Fab-terminal parts. Protein A (Mr 42,000) is the only well-characterized S. aureus cell wall protein, and its structure is known in detail. A considerable number of biological properties of protein A has been demonstrated. Most of these properties seem to be a consequence of the complement activation induced by protein A-IgG complexes. The role of protein A in the phagocytosis of S. aureus is complex. By complement consumption protein A has been found to inhibit the phagocytosis of staphylococci by polymorphonuclear leucocytes. However, it has been demonstrated that protein A-containing staphylococci bind to surface IgG on human alveolar and peritoneal macrophages and thereby promote phagocytosis by these cells. This phenomenon might explain the increased virulence of S. aureus in the presence of human IgG in experimental peritonitis in mice. Fibrinogen binds to a surface structure on S. aureus, designated clumping factor as the binding results in clumping of whole bacteria. Recently, a glycoprotein (Mr of about 400,000) has been isolated from S. aureus. This glycoprotein seems to be the clumping factor. It binds to fibrinogen, inhibits the fibrinogen induced clumping, and seems to be a S. aureus specific, surface component. The isolated component activates human complement in vitro. Also, it induces protection against S. aureus peritonitis in immunized mice. The presence of fibrinogen and an unknown human plasma component increases the virulence of S. aureus in experimental peritonitis in mice, but the role of fibrinogen in human S. aureus infection is unknown. Fibronectin binds to a surface protein on S. aureus, and this binding also results in the clumping of the bacteria. The binding site(s) for fibronectin is different from the binding sites for fibrinogen and IgG. A fibronectin-binding protein (Mr 197,000) has been isolated from S. aureus by affinity chromatography. This protein binds fibronectin and inhibits the fibronectin induced S. aureus clumping. No other biological properties of this protein have yet been demonstrated. The binding of fibronectin to S. aureus opsonize the bacteria for polymorphonuclear leucocytes. The opsonic capacity is, however, low compared to other serum opsonins. It has been suggested that fibronectin plays a role in the attachment of S. aureus, but further studies are needed.(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Proteins↗
PubMed1986

A one-year survey of nosocomial bacteraemia at a Danish university hospital.

A 1-year prospective study of nosocomial bacteraemia was performed at Hvidovre Hospital with special reference to frequency, focus of infection and prognosis. All patients were examined clinically in order to confirm the bacteraemia. In total, 98 hospital-acquired bacteraemias were observed, giving an incidence rate of 0.28%. Bacteraemia due to Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis predominated. The overall mortality was 38%; 65% of the patients with S. aureus bacteraemia died, 25% due to the bacteraemia. The most common types of infection were urinary tract infections and intravenous catheter infections. Fifty-five of the bacteraemias were caused by foreign bodies, mostly urinary catheters and intravenous catheters, and in 14 cases the focus was unknown. The patient population was severely ill patients. We conclude that nosocomial bacteraemia occurs specially in severely ill patients often preceded by indwelling urinary or intravenous catheters. The patients seldom die due to the bacteraemia, but they die with concomitant bacteraemia.

Adolescent↗
PubMed1986

Enzyme-linked immunosorbent assay for detection of Staphylococcus epidermidis antibody in experimental S. epidermidis endocarditis.

The immune response against Staphylococcus epidermidis, as determined by an enzyme-linked immunosorbent assay, was evaluated in experimental S. epidermidis infections in rabbits. Antigens from 8 of 10 clinical S. epidermidis strains detected significant antibody production in five rabbits immunized with different strains of S. epidermidis and in five of six rabbits with experimental endocarditis caused by four different strains. The antigens from two strains detected antibody production in all rabbits, and strain ATCC 14990 discriminated best between positive and negative samples. Consecutive blood samples from rabbits with endocarditis and control rabbits with bacteremia, which were successfully prevented from developing endocarditis by using prophylactic antibiotics, were examined by using an enzyme-linked immunosorbent assay and an ultrasonic extract of strain ATCC 14990 as the antigen. This assay discriminated between rabbits with endocarditis and rabbits with uncomplicated bacteremia. Antibody production was detected as early as 3 days after the onset of infection in rabbits with endocarditis.

Animals↗
PubMed1986

Bacteria and their products release histamine and potentiate mediator release: new aspects in airway diseases.

The possibility that bacteria and their products play a role in airway diseases, due to their capacity to release histamine, was investigated in blood leucocytes from patients suffering from respiratory diseases and from healthy individuals. The results clearly show that bacteria release histamine by immunological and non-immunological mechanisms and that endotoxins enhance mediator release caused by allergens in allergic patients or by bacteria in persons sensitized to these organisms. Furthermore, a great increase is obtained in mediator release by the combination of immunological and non-immunological mechanisms.

Adult↗