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Biomedical subjects

J Dankert

Publications and source records attributed to J Dankert.

At least 199 records · Page 11Linked to original sources
PubMed1993

[Carrier state and spread of methicillin resistant Staphylococcus aureus following hospital discharge].

OBJECTIVE: To determine whether patients colonised with methicillin-resistant Staphylococcus aureus (MRSA) remain carriers after discharge from hospital and whether transmission of MRSA to the community occurs. DESIGN: Prospective and retrospective study. PATIENTS AND METHODS: Fifteen patients colonized with MRSA and admitted to the University Hospital of the University of Amsterdam between January 1991 and September 1992 were screened for MRSA after their discharge from hospital (350 days median). Their family members and domestic animals were screened at the same time. RESULTS: Cultures from 50 people (15 ex-patients, 35 family members) and II animals were investigated for presence of MRSA. Two (13%; 95% confidence interval: 2-40%) patients still carried the MRSA strain. Both still had risk factors for carriage of the bacteria. No MRSA was found in cultures from family members or domestic animals. CONCLUSIONS: Long term carriage of MRSA outside the hospital occurs infrequently and is closely related to predisposing factors of the patient. Transmission of MRSA to healthy individuals could not be demonstrated.

Adult↗
PubMed1993

[Secondary cases of meningococcal disease in The Netherlands, 1989-1990; a reappraisal of chemoprophylaxis].

OBJECTIVE: To assess the secondary attack rate (SAR) of meningococcal disease among the household contacts of primary patients and to describe the use of chemoprophylaxis in the Netherlands. DESIGN: Descriptive, nation-wide survey. METHODS: Information was collected of patients with meningococcal disease, reported between April 1st, 1989 and April 30th, 1990, and their household contacts. A household contact suffering from meningococcal disease between 24 hours and 1 month after hospital admission of the primary patient, was considered to be a secondary case. Chemoprophylaxis was considered appropriate if rifampicin or minocycline had been prescribed to all household contacts within a maximum of one day after admission of the primary patient. RESULTS: There were 5 secondary cases (SAR: 0.3%). Chemoprophylaxis was prescribed to 627 of 1130 household contacts (55%). Of those the prophylaxis was considered appropriate in 46%. 2 secondary cases were not given any prophylaxis, 2 received penicillin and 1 rifampicin. Of the primary patients, 6% were given prophylaxis during their hospital stay. All meningococci, isolated from pairs of secondary and primary patients, were rifampicin sensitive. CONCLUSIONS: The SAR of meningococcal disease in the Netherlands is similar to that in other countries. Although prescription of chemoprophylaxis is not recommended by the government, it is prescribed to 55% of the household contacts, and in almost half of these instances it was considered to be appropriate. Chemoprophylaxis is rarely prescribed to primary patients. Recommendations concerning chemoprophylaxis in the Netherlands are in need of reappraisal. Based on the results from this study and the literature, the prescription of chemoprophylaxis to all household contacts of a patient with meningococcal disease, and to the index patient, is recommended.

Adult↗
PubMed1993

[Complement deficiencies and meningococcal disease in The Netherlands].

OBJECTIVE: To determine the prevalence of complement system deficiencies in patients who have survived a Neisseria meningitidis infection. DESIGN: Retrospective. SETTING: Reference laboratory for bacterial meningitis of the University of Amsterdam and the National Institute of Public Health and Environmental Protection. METHOD: Out of the files of the laboratory 187 patients who had experienced a meningococcal infection in the Netherlands between 1959-1990 were selected in two groups according to the infecting bacterial strain: 97 patients with a serogroup X, Y, Z, W135, 29E, or non-groupable strains and 90 patients with an infection due to serogroup A or C. The patients were asked for their cooperation by their family doctor and one of us visited the patients at home to take blood samples. The complement activity was studied with a haemolysis in gel test and with an assay of haemolytic activity in free solution. RESULTS: Complement deficiency was present in 18% of the 187 patients who had experienced a meningococcal infection. The highest prevalence was found in patients older than 10 years who had developed infections due to serogroups X, Y, W135, or non-groupable strains (45%). Of the patients with a serogroup A or C infection, 3% had an complement deficiency. Of the complement deficiencies, 42% concerned a component of the alternative pathway, 12% a deficiency of C3, and 46% a component of the terminal route. The most commonly found deficiencies were properdin deficiency (39%) and C8 deficiency (18%). 30% of the complement deficient patients reported other family members having experienced meningitis. Recurrent meningitis was only observed in patients with terminal route deficiencies. CONCLUSION: We recommend that patients with a meningococcal infection due to serogroups X, Y, W135 or non-groupable strains should be screened for complement deficiency.

Adolescent↗
PubMed1993

Genetic analysis of the diversity in outer membrane protein P2 of non-encapsulated Haemophilus influenzae.

The molecular basis for the diversity of the major outer membrane protein (MOMP) P2 of non-encapsulated Haemophilus influenzae was analyzed by direct sequencing of fragments of the P2 genes, obtained by the polymerase chain reaction. Genetically divergent H. influenzae strains were isolated from patients with otitis media and from infected patients with chronic obstructive pulmonary disease (COPD). The nucleotide sequences of these P2 genes were determined and compared with P2 gene sequences of three non-encapsulated strains and with the P2 gene of encapsulated H. influenzae type b. Variation in the nucleotide sequence of the P2 genes of non-encapsulated H. influenzae was localized in eight distinct regions which were interchanged with relatively conserved regions. Regions 2, 4, 5 and 8 were found to be hypervariable, since they were characterized by multiple deletions or substitutions of nucleotides. According to the proposed structure of MOMP P2 the variable regions were localized in eight loop structures exposed at the outside of the outer membrane. Loops 2, 4, 5 and 8 were hypervariable in all isolates whereas loop 6 varied only in isolates from COPD patients with persistent infections.

Amino Acid Sequence↗
PubMed1993

One year follow-up study to assess the prevalence and incidence of Lyme borreliosis among Dutch forestry workers.

A one-year serological and clinical follow-up study was conducted to assess the prevalence and incidence of asymptomatic and symptomatic infection with Borrelia burgdorferi among 151 Dutch forestry workers. The prevalence of antibodies to Borrelia burgdorferi among the forestry workers and among office employees as control group was compared. Antibodies to Borrelia burgdorferi were detected by enzyme immunoassay. Forestry workers were examined physically at the start of the study. Clinical follow-up of forestry workers whose first blood sample was positive and of persons showing seroconversion was done by telephone interview. If Lyme borreliosis was suspected, clinical and laboratory data were obtained. The seroprevalence was significantly higher among forestry workers (28%) than among controls (5%). Of 127 forestry workers who were examined, 7 (18%) of the 39 seropositive persons but none of the seronegative persons had a history of Lyme borreliosis. None of 32 asymptomatic seropositive forestry workers had developed Lyme borreliosis one year later. The incidence of infection with Borrelia burgdorferi as demonstrated by seroconversion among 95 initially seronegative forestry workers was 5%. None of them had Lyme borreliosis. Infection with Borrelia burgdorferi among forestry workers is frequent but seems to take a benign course.

Adult↗
PubMed1993

Meningococcal disease in The Netherlands, 1958-1990: a steady increase in the incidence since 1982 partially caused by new serotypes and subtypes of Neisseria meningitidis.

In order to explain a threefold increase in the incidence of meningococcal disease in the Netherlands during the 1980s, we serotyped and subtyped Neisseria meningitidis isolates recovered between 1958 and 1990 from > 3,000 patients with systemic disease. No single strain could be held responsible for the increase. Apart from the newly introduced strain B:4:P1.4, which became the most prevalent phenotype in 1990 (21% of all isolates), the majority of the cases in 1990 were caused by many different strains that were already present in the Netherlands before 1980. For the period 1980-1990, a shift in the age distribution of patients with meningococcal disease from younger to older age categories was found, particularly with regard to cases due to meningococci of serogroup B; this shift is explained by the changing distribution of serotypes and subtypes within serogroup B. A polyvalent group B, class 1 outer-membrane-protein vaccine of a stable composition could theoretically have prevented approximately 80% of all group B meningococcal infections in the Netherlands during the past 30 years.

Adolescent↗
PubMed1993

Different genospecies of Borrelia burgdorferi are associated with distinct clinical manifestations of Lyme borreliosis.

Borrelia burgdorferi sensu lato has been subdivided into three genospecies: B. burgdorferi sensu stricto, B. garinii, and B. burgdorferi group VS461. Sixty-eight isolates cultured from patients and 26 strains from ticks were characterized with use of SDS-PAGE, western blotting, and rRNA gene restriction analysis. Fifty-seven of 58 strains obtained from the skin of 70 patients who had erythema migrams or acrodermatitis chronica atrophicans were of group VS461, whereas the genotype of the remaining strain was unidentifiable. Of 10 strains cultured from CSF (n = 3) and skin (n = 7) of 20 patients with extracutaneous symptoms of Lyme borreliosis, nine were B. garinii and one was B. burgdorferi sensu stricto. Of these 20 patients, 17 had neuroborreliosis, one had arthritis and carditis, one had myalgia, and one had erythema and arthralgia. All 26 isolates from ticks were of group VS461. In conclusion, infections due to group VS461 and B. garinii are associated with cutaneous and extracutaneous symptoms, respectively. Our findings suggest that B. burgdorferi genotypes have different pathogenic potentials.

Acrodermatitis↗
PubMed1993

Immunogenicity of the meningococcal stress protein MSP63 during natural infection.

Acute- and convalescent-phase sera from 40 patients with meningococcal disease were evaluated for immunoreactivity with the meningococcal member of the hsp60 stress protein family. The IgG response was measured by ELISA, using bacterial cell lysate of the corresponding patients' strain, and purified hsp60 proteins from Neisseria meningitidis (MSP63), Escherichia coli (GroEL) and Mycobacterium bovis BCG (65K) as antigens. Analysis of the antibody responses revealed that 24/35 patients (69%) with elevated anti-meningococcal titres, generated anti-MSP63 antibodies during the time course of infection. Twelve of these patients generated antibodies specific for MSP63, in six patients anti-MSP63 levels exceeded anti-GroEL/65K antibodies. In the remaining six patients, equal levels of anti-MSP63 and anti-GroEL/65K were measured. We conclude that MSP63 is expressed and immunogenic during natural meningococcal infection, and that individual subjects have a restricted response to the antigen, resulting in the recognition of Neisseria-specific hsp60 epitopes and/or cross-reactive hsp60 determinants.

Adolescent↗
PubMed1993

N-acetyl-D-glucosamine medium improves recovery of Haemophilus influenzae from sputa of patients with cystic fibrosis.

A modified selective medium supplemented with N-acetyl-D-glucosamine (NAG), hemin, and NAD plus two cefsulodin disks, for primary isolation of nonencapsulated Haemophilus influenzae from sputum of patients with cystic fibrosis, is described. Isolation of H. influenzae from this medium, designated NAG medium, was compared with recovery by standard media and immunochemical detection of H. influenzae with monoclonal antibody 8BD9. The H. influenzae recovery rate increased from 31% with standard media to 42% with NAG medium. H. influenzae was detected by immunoperoxidase staining in 54% of the sputum specimens. The results of this study demonstrate that NAG medium improves H. influenzae recovery, although immunoperoxidase staining is superior for detection of H. influenzae from sputum of cystic fibrosis patients.

Acetylglucosamine↗
PubMed1993

Diagnosis of intestinal and disseminated microsporidial infections in patients with HIV by a new rapid fluorescence technique.

AIMS: To assess the value of a new rapid fluorescence method for the diagnosis of microsporidiosis in HIV seropositive patients. METHODS: Microsporidian spores in stools were demonstrated by using the fluorochrome stain Uvitex 2B. The new technique was evaluated in three groups of HIV seropositive patients with diarrhoea. Group 1: 19 patients with biopsy confirmed E bieneusi infection (186 stool samples); group 2: 143 consecutive patients from whom faeces were submitted for routine investigation of diarrhoea (318 samples); group 3: 16 patients with small intestinal biopsy specimens negative for microsporidia (55 samples). The new method was used to monitor spore shedding during experimental treatment with paromomycin and albendazole in four patients. RESULTS: Brightly fluorescent spores were detected in all stool samples of patients in group 1. In group 2 16 (11%) patients had spores in their stool samples. E bieneusi was found in 11 patients; in the other five another genus of microsporidia, Encephalitozoon, was recognised. Encephalitozoon spores were also found in the urine of three of these patients and in the maxillary sinus aspirate of two of them, suggesting disseminated infection. The results were confirmed by electron microscopic examination. In group 3 negative biopsy specimens were confirmed by negative stool samples in all cases. Treatment with albendazole and paromomycin did not affect the spore shedding in three patients with E bieneusi infection. By contrast, in a patient with Encephalitozoon sp infection albendazole treatment resulted in clinical improvement together with complete cessation of spore excretion in the stool. CONCLUSION: The Uvitex 2B fluorescence method combines speed, sensitivity, and specificity for the diagnosis and treatment evaluation of intestinal and disseminated microsporidiosis.

Albendazole↗
PubMed1992

Identification and characterization of a cross-reactive and a unique B-cell epitope on the hsp60 homologue from Neisseria gonorrhoeae.

Two monoclonal antibodies (G6 and 7B), generated against a 63-kDa stress protein (GSP63) from Neisseria gonorrhoeae strain VP1, were used to investigate the antigenic heterogeneity of GSP63 among the Neisseriaceae and its antigenic relationship with the Hsp60 heat-shock protein family. Immunoblotting experiments demonstrated antibody reactivity with all pathogenic Neisseria tested and with some of the commensal strains. One of the antibodies (7B) cross-reacted with the 65-kDa M. bovis BCG heat-shock protein and with 14 out of the 21 similarly sized proteins in other bacterial species. The other antibody (G6) specifically recognized neisserial GSP63 homologues. These results demonstrate that GSP63 is a conserved neisserial antigen bearing both a unique neisserial B-cell epitope and a more widely distributed Hsp60 epitope.

Animals↗
PubMed1992

Absence of Lyme borreliosis among patients with presumed Bell's palsy.

In a prospective study, 69 patients with a presumed idiopathic (Bell's) peripheral facial palsy were clinically and serologically evaluated for the presence of Lyme borreliosis. In addition, their clinical spectrum was compared with clinical manifestations collected retrospectively in nine patients with symptomatic peripheral facial palsy due to Lyme borreliosis. The seroprevalence of Borrelia burgdorferi antibodies, determined by flagellum enzyme-linked immunosorbent assay, among 69 patients with idiopathic peripheral facial palsy (6%) and 153 healthy controls (4.5%) was not significantly different (odds ratio, 1.28; 95% confidence interval, 0.27 to 5.25). None of the patients with idiopathic peripheral facial palsy had or experienced the development of Lyme borreliosis. All patients with Lyme peripheral facial palsy had additional manifestations not present in patients with idiopathic peripheral facial palsy. These findings show that patients with a Lyme peripheral facial palsy can be differentiated from patients with idiopathic peripheral facial palsy by clinical examination. Therefore, screening of antibodies to B burgdorferi among patients with idiopathic peripheral facial palsy without additional manifestations is not recommended.

Adolescent↗
PubMed1992

Physicochemical characterization of Escherichia coli. A comparison with gram-positive bacteria.

Eight Escherichia coli strains were characterized by determining their adhesion to xylene, surface free energy, zeta potential, relative surface charge, and their chemical composition. The latter was done by applying X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR). No relationship between the adhesion to xylene and the water contact angles of these strains was found. Three strains had significantly lower surface free energies than the other strains. Surface free energies were either obtained from polar and dispersion parts or from Lifshitz-van der Waals and acid/base parts of the surface free energy. A correlation (r = 0.97) between the polar parts and the electron-donor contributions to the acid/base part of the surface free energy was found. The zeta potentials of all strains, measured as a function of pH (2-11), were negative. Depending on the zeta potential as a function of pH, three groups were recognized among the strains tested. A relationship (r = 0.84) was found between the acid/base component of the surface free energy and the zeta potential measured at pH = 7.4. There was no correlation between results of XPS and IR studies. Data from the literature of XPS and IR studies of the gram-positive staphylococci and streptococci were compared with data from the gram-negative E. coli used in this study. It appeared that in these three groups of bacteria, the polysaccharide content detected by IR corresponded well with the oxygen-to-carbon ratio detected by XPS.

Anion Exchange Resins↗
PubMed1992

Changes in the distribution of Haemophilus influenzae type b clones associated with widespread infant vaccination in Finland.

Isolates from 646 consecutive Finnish Haemophilus influenzae type b (Hib) patients with systemic disease, collected before and during large-scale vaccinations with Hib conjugate vaccines, were analyzed by major outer membrane protein (OMP) subtyping, lipopolysaccharide (LPS) serotyping, and biotyping (BT). Strains with OMP-BT-LPS combinations (clones) 1-I-1 and 1c-I-1 disappeared at the same rate as the disease they were associated with. A preferential decrease in the number of isolates of clone 1-II-1 was recorded, whereas the reduction in disease caused by strains of clone 1-II-9 occurred at a lower rate than expected. The latter clone occurred mainly in the most densely populated area of Finland. Strains belonging to all the common Hib clones were isolated from the 16 infants who acquired Hib disease despite being (partially) vaccinated. Thus, Hib clones disappeared during mass vaccination with conjugate vaccines, although at different rates.

Adolescent↗
PubMed1992

Bacterial migration along solid surfaces.

An in vitro system was developed to study the migration of uropathogenic Escherichia coli strains. In this system an aqueous agar gel is placed against a solid surface, allowing the bacteria to migrate along the gel/solid surface interface. Bacterial strains as well as solid surfaces were characterized by means of water contact angle and zeta potential measurements. When glass was used as the solid surface, significantly different migration times for the strains investigated were observed. Relationships among the observed migration times of six strains, their contact angles, and their zeta potentials were found. Relatively hydrophobic strains exhibited migration times shorter than those of hydrophilic strains. For highly negatively charged strains shorter migration times were found than were found for less negatively charged strains. When the fastest-migrating strain with respect to glass was allowed to migrate along solid surfaces differing in hydrophobicity and charge, no differences in migration times were found. Our findings indicate that strategies to prevent catheter-associated bacteriuria should be based on inhibition of bacterial growth rather than on modifying the physicochemical character of the catheter surface.

Bacterial Adhesion↗
PubMed1992

Identification and molecular analysis of a 63-kilodalton stress protein from Neisseria gonorrhoeae.

Iron limitation, glucose deprivation, and growth under low oxygen supply (environmental stress) increased the expression of several proteins of Neisseria gonorrhoeae, including a 63-kilodalton protein identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This gonococcal stress protein (GSP63) was detected in the cytosol and copurified with lithium acetate-derived outer membranes. Successful purification of the protein was achieved by sucrose density gradient centrifugation and by chromatography on phenyl-Sepharose. Gel filtration of the purified protein revealed a molecular weight of approximately 450,000, suggesting that in its native state, the protein consists of a multimer of six to eight subunits. Isoelectric focusing indicated a pI of 5.2. Immunoblotting experiments using a polyclonal antiserum raised against the purified protein demonstrated cross-reactivity with a protein of the same electrophoretic mobility as GSP63 in all eight gonococcal isolates tested. N-terminal amino acid sequencing of the protein revealed up to 65% homology with members of the Hsp60 heat shock protein family, suggesting that GSP63 is related to this group of proteins. This relationship was further substantiated by the immunological cross-reactivity of GSP63 with mycobacterial Hsp60 and the ATP-binding activity of the gonococcal stress protein.

Acetates↗