Biomedical subjects

F Espersen

Publications and source records attributed to F Espersen.

176 records · Page 10Linked to original sources

PubMed1982

Isolation of a fibronectin-binding protein from Staphylococcus aureus.

Fibronectin ("cold-insoluble globulin") has been suggested to play a role in cell-to-cell and cell-to-substratum adhesions. The 70-kilodalton terminal part of human fibronectin has recently been shown to bind to Staphylococcus aureus. In the present study, a fibronectin-binding protein was purified from sonicated S. aureus strain E2371 by affinity chromatography on fibronectin-Sepharose. The fibronectin-binding protein was isolated from an extract of sonicated S. aureus containing at least 57 different proteins as determined by crossed immunoelectrophoresis in antibodies to sonicated S. aureus. The fibronectin-binding protein was released from fibronectin-Sepharose by carbamide (8 M). No impurities in the final preparation could be detected when tested in crossed immunoelectrophoresis. By polyacrylamide gel electrophoresis in both reduced and unreduced gels, the protein showed two bands with relative molecular masses of 197,000 and 60,000, respectively. A complex between the purified S. aureus protein and fibronectin could be demonstrated by crossed immunoelectrophoresis both in monospecific antibodies against fibronectin and in S. aureus polyspecific antibody.

Animals↗

PubMed1982

Staphylococcus aureus antibodies in patients with staphylococcal septicemia. Comparisons between solid-phase radioimmunoassay and crossed immunoelectrophoresis.

Antibody responses against teichoic acids and other antigens from Staphylococcus aureus in 23 patients with septicemia and 8 patients with endocarditis caused by S. aureus were investigated. Both methods used--solid-phase radioimmunoassay (SPRIA) and crossed immunoelectrophoresis (CIE)--detected significantly higher titres in the endocarditis group. The SPRIA method utilized a sonicated extract of S. aureus, strain Wood 46 for the quantitation of antibodies. In CIE precipitating anti-teichoic acid antibodies were measured. There was no absolute correlation between the two assays, indicating that the antibodies measured were directed at partly different antigens. The two tests might be complementary to each other when used in combination.

Antibodies, Bacterial↗

PubMed1981

Pneumonia due to Staphylococcus aureus during mechanical ventilation.

The incidence of pneumonia due to Staphylococcus aureus in patients treated with mechanical ventilation in an intensive-therapy unit was investigated in a prospective study. Of 295 ventilated patients treated during one year, 17 developed S. aureus pneumonia and 26 developed colonization of lower airways by S. aureus. Neurosurgical patients treated with hyperventilation, sedation, cooling, and steroids had a significantly higher frequency of both S. aureus pneumonia (25.9%) and S. aureus colonization (27.8%) compared with other ventilated patients (1.2% and 4.6%, respectively). The epidemiologic and clinical findings indicate that neurosurgical patients have an increased susceptibility to infections of airways with S. aureus.

Hospital Departments↗

PubMed1981

Cross-reactions between Staphylococcus epidermidis and 23 other bacterial species.

By quantitative immunoelectrophoretic methods, 43 antigens were found in a mixture of sonicated preparations of four Staphylococcus epidermidis strains, using corresponding rabbit antiserum. Two of the antigens were identified as cell wall teichoic acid and a peptidoglycan antigen, respectively. Using this antigen/antibody reference system, cross-reactions between S. epidermidis antigens and antigens from other bacterial species were investigated. Fourteen of the S. epidermidis antigens cross-reacted with antigens from all S. aureus strains investigated. Only few cross-reactions were found between S. epidermidis and bacteria not belonging to the Micrococcaceae. The antigenic relatedness, expressed as a matching coefficient, seems promising for taxonomic work.

Antigens, Bacterial↗

PubMed1981

Precipitating antibodies against Staphylococcus aureus in serum from patients with staphylococcal septicaemia, investigated by means of quantitative immunoelectrophoretic methods.

Crossed immunoelectrophoresis was employed in the study of precipitating antibodies against Staphylococcus aureus in sera from 46 patients with S. aureus septicaemia. The occurrence and titres of antibodies were compared to previously reported findings for normal persons. Ten infection-specific precipitins were detected. However, most of these precipitins were detected in low titres and could only be detected during convalescence. When antibodies against a single antigen were measured, titres above the normal level were found in 39.1% - 65.2% of the patients. When the total number of precipitins in each serum was compared to findings in serum from normal persons, 54.3% of the patients had a higher value. Most promising was the precipitin score, considering both the number of precipitins and their titres. This score showed an early rise and was increased above the normal level in 82.6% of the patients. The antibody response against individual S. aureus antigens varied from person to person both concerning titres and time course.

Adolescent↗

PubMed1981

Clumping of Staphylococcus aureus by human fibronectin.

Clumping of different staphylococci by fibronectin and other purified plasma proteins has been investigated. Purified fibronectin was capable of clumping Staphylococcus aureus strains in concentrations identical with concentrations of fibronectin in human plasma. S. epidermidis and S saprophyticus were not clumped by fibronectin. The binding of fibronectin to S. aureus was not mediated by protein-A, as a strain lacking protein-A clumped in the presence of fibronectin, and the presence of IgG could not inhibit the clumping of S. aureus strains. The fibronectin-binding component on the staphylococcal cell wall seems to be unrelated to the fibrinogen-binding clumping factor.

Agglutination↗

PubMed1981

Normally-occurring precipitating antibodies against Staphylococcus aureus in human serum and colostrum.

Crossed immunoelectrophoresis was used to study precipitating antibodies against Staphylococcus aureus in sera from 263 normal persons and in 10 colostrum samples. A polyspecific protein-A free S. aureus antigen preparation and a corresponding rabbit antiserum constituted the reference system. All the sera contained precipitins against 6-10 S. aureus antigens. One of these was teichoic acid, and the titre of antibodies against cell wall teichoic acid varied from person to person, in contrast to other commonly occurring antibodies. The precipitin score, which expresses the number and titre of precipitins in each serum, increased with age. Colostrum contained 3 precipitins, which were not present in the corresponding maternal sera.

Adolescent↗

PubMed1981

Staphylococcus aureus pneumonia as a complication during treatment of neurosurgical patients with mechanical ventilation.

During 1978 a high incidence of Staphylococcus aureus pneumonia (11/54) was found in patients treated with mechanical hyperventilation for cerebral lesions, compared to other patients on mechanical ventilation in the same ward (1/148). Patients with cerebral lesions also had an increased risk of colonization with Staph. aureus. The patients were colonized and infected with different phage types of Staph. aureus. These factors in combination with the epidemiological data indicate that the increased infection rate is due to a specific impairment of the local defence mechanism in the respiratory tract of these patients and not to an increased exposure to epidemic strains of Staph. aureus. The course of the infections indicates that microscopical examination of material from endotracheal suctions is important in order to diagnose the infection as early as possible.

Humans↗

PubMed1980

Quantitative immunoelectrophoretic analysis of Salmonella typhi antigens and of corresponding antibodies in human sera.

By quantitative immunoelectrophoretic methods, 86 different antigens were found in sonicated preparations of a Salmonella typhi, using corresponding rabbit antiserum. Lipopolysaccharide was identified, and 5 other antigens characterized. Antibodies against a total of 19 S. typhi antigens were found in human sera. The antibody response in patients with typhoid fever was significantly more pronounced compared to that in normal persons. When the antibody response was expressed as a precipitin score, the predictive value of both a positive (precipitin score greater than or equal to 8) test and a negative test was 100%, when sera from patients suffering from typhoid fever were compared with sera from normal persons.

Animals↗

PubMed1980

Cross-reactions between Salmonella typhi and 24 other bacterial species.

Cross-reactions between antigens from S. typhi and 24 other bacterial species were studied by quantitative immunoelectrophoretic methods. A sonicated S. typhi antigen preparation and a corresponding pooled rabbit antiserum regularly presenting 86 immunoprecipitates were used as a reference system. Antigens from Enterobacteriaceae cross-reacted intensively with the S. typhi antigens. No cross-reactions between S. typhi and antigens from gram-positive bacteria were found, and only a few cross-reactions with antigens from gram-negative bacteria outside the Enterobacteriaceae. The taxonomic perspectives of the immunoelectrophoretic approach are stressed by results showing that the number of cross-reacting antigens between S. typhi and other Enterobacteriaceae was positively correlated to the number of identical reactions in a collection of 28 biochemical tests.

Antigens, Bacterial↗

PubMedDate not supplied

Dicloxacillin and flucloxacillin: pharmacokinetics, protein binding and serum bactericidal titers in healthy subjects after oral administration.

The pharmacokinetics of dicloxacillin and flucloxacillin were studied in 12 healthy volunteers after oral administration. The participants received a single dose of either dicloxacillin (0.5 g, 0.75 g or 1.0 g) or flucloxacillin (0.75 g) in a cross-over fashion. Antibiotic concentrations were determined in serum and urine by bioassay and followed for 8 and 24 h, respectively. The three dicloxacillin dosages showed no significant differences for the serum elimination half-lives (t1/2 beta, median: 72 min). Comparing 0.75 g flucloxacillin with the same dose of dicloxacillin, no significant differences between the values of Cmax, t1/2 beta and AUC were found. Protein binding as determined by ultrafiltration in pooled serum was 94.7-96.2% for flucloxacillin and 96.4-97.2% for dicloxacillin. The serum bactericidal titers were similar for the two drugs. In conclusion, dicloxacillin and flucloxacillin showed similar pharmacokinetic behavior after 0.75 g doses in human volunteers.

Administration, Oral↗

PubMedDate not supplied

Evaluation of calibrated 1 and 10 microl loops and dipslide as compared to pipettes for detection of low count bacteriuria in vitro.

Criteria for defining urinary tract infection have changed as the importance of low count bacteriuria in patients with symptoms of infection has been recognized. Little has been published, however, regarding the ability of routine laboratory methods to meet this new challenge. We compared 1 microl and 10 microl calibrated plastic loops (Nunc, Denmark), to a commonly used dipslide method (Uricult, Orion, Finland) using a 0.1 ml pipette as the gold standard. Four typical uropathogens, E. coli, P. aeruginosa, S. saprophyticus and E. faecalis, were mixed in pooled human urine in numbers representing low counts, i.e. 10(2), 10(3), and 10(4), together with 10(5) colony-forming units (cfu)/ml, and sampling with the four methods was performed 20 times for each with each bacterium and each dilution. Colony counts showed that in many cases the 1 microl loop did not deposit any bacteria on the agar plate when colony counts were lower than 10(4) cfu/ml. The 10 microl loop constantly deposited 1.5 times higher numbers of bacteria than predicted, which correlated with the results of weighing the amount of water sampled, i.e. 15.24 (1.55) microg (mean (SD)). The dipslide counts correlated with the 10 microl loop although the agar mounts on the slides absorbed water equal to about 200 microl. There were no significant differences in the counts of the four different bacteria. Variation coefficients increased with decreasing volumes sampled, but the 10 microl loop was found sufficiently exact to detect counts from 10(3) to 10(4), since only 10-fold multiples are usually reported for urine cultures.

Bacteriological Techniques↗

PubMedDate not supplied

Changing pattern of bone and joint infections due to Staphylococcus aureus: study of cases of bacteremia in Denmark, 1959-1988.

Of the 15,170 cases of bacteremia due to Staphylococcus aureus that occurred in Denmark between 1959 and 1988, we review 525 cases of acute hematogenous osteomyelitis and 185 cases of septic arthritis that developed subsequent to the bacteremia and 134 cases of contiguous osteomyelitis in which the bacteremia developed secondarily. The pattern of acute infections of bones and joints has changed over the three decades studied. The frequency of secondary bone or joint infections due to S. aureus bacteremia has changed, as have the phage-type pattern and antibiotic resistance of the infective strains. The prevalence of hospital-acquired cases has increased and the age distribution of patients has changed, as is reflected in an increasing number of older patients. The localization of hematogenous osteomyelitis has shifted, and the vertebral column is now the most common site of infection. The rate of chronic cases of osteomyelitis that occur following acute hematogenous osteomyelitis has been reduced from 34% to 6%. The mortality associated with S. aureus bacteremic infections of bones or joints is low compared to that associated with other cases of S. aureus bacteremia.

Acute Disease↗

PubMedDate not supplied

Detection of penicillin resistance in Streptococcus pneumoniae by diffusion tests.

Four different diffusion tests used to detect penicillin resistance in Streptococcus pneumoniae were evaluated for 34 penicillin-susceptible pneumococci (MIC < 0.1 microgram/ml), 35 intermediate pencillin-resistant (MIC 0.1-1.0 microgram/ml) and 23 penicillin-resistant strains (MIC > 2 micrograms/ml). The 1 microgram oxacillin disk from AB Biodisk, the 1 microgram oxacillin Neo-Sensitabs from Rosco, the 5 micrograms penicillin Low Neo-Sensitabs and the penicillin E test were tested on Mueller-Hinton blood agar, PDM Antibiotic Sensitivity Medium II supplemented with blood, and Danish Blood Agar. MICs obtained by the agar dilution method were used as reference. The 1 microgram oxacillin AB Biodisk was able to separate all the penicillin-susceptible pneumococci correctly from those with reduced penicillin susceptibility (MIC > or = 0.1 microgram/ml), whereas use of the 1 microgram oxacillin Neo-Sensitabs resulted in high frequencies (14-29%) of intermediate penicillin-resistant strains interpreted as penicillin susceptible. The 5 micrograms penicillin Low Neo-Sensitabs proved completely useless for detecting penicillin resistance in pneumococci. High rates of agreement (82-93%) were found between the penicillin E test and the reference MIC determination method on all the tested media.

Diffusion↗