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Biomedical subjects

L J Sabbe

Publications and source records attributed to L J Sabbe.

18 recordsLinked to original sources
PubMed2000

Increasing resistance to fluoroquinolones in escherichia coli from urinary tract infections in the netherlands.

In continuous surveillance of routine samples from five Dutch laboratories, we studied resistance to the antibiotics most commonly prescribed for urinary tract infections (UTI) in The Netherlands, namely norfloxacin, amoxycillin, trimethoprim and nitrofurantoin, from 1989 to 1998 in >90000 Escherichia coli isolates. Resistance to norfloxacin increased from 1.3% in 1989 to 5.8% in 1998. Multiresistance, defined as resistance to norfloxacin and at least two of the other three antibiotics, increased from 0.5% in 1989 to 4. 0% in 1998. Multivariate analysis of the norfloxacin resistance demonstrated that this yearly increase (the odds ratio was 1.0 in 1989, 1.6 in 1992, 2.9 in 1995 and 6.1 in 1998) was independent of other determinants of resistance to norfloxacin, such as age, gender and origin of the isolate. Analysis of strata, classified by year, age and gender, demonstrated an association between prescription of fluoroquinolones (defined daily doses per case of UTI) and resistance to norfloxacin in E. coli (P < 0.001). There was no significant association with the prescription of nitrofuran derivatives (nitrofurantoin) and trimethoprim with or without sulphamethoxazole. The yearly increase of resistance to fluoroquinolones in E. coli from UTI may stem from increased prescription of fluoroquinolones for UTI. Resistance of E. coli to these agents is likely to increase further as fluoroquinolone use increases in future.

Adolescent↗
PubMed1999

Clinical spectrum of infections due to the newly described Actinomyces species A. turicensis, A. radingae, and A. europaeus.

Over a 7-year period, we isolated 294 Actinomyces-like organisms (ALOs) which were not clearly identifiable. Using well-defined probes coding for sequences specific for recently described Actinomyces species (A. turicensis, A. radingae, and A. europaeus), we were able to identify 128 strains. The majority belonged to the A. turicensis species. A. radingae was found only in patients with skin-related pathologies. A. europaeus was also detected in patients with urinary tract infections. The main sources of A. turicensis were genital infections, followed by skin-related and urinary tract infections. Additional clinical pictures were appendicitis, cholecystitis, ear, nose, and throat infections, and bacteremia. In a small number of patients these ALOs were found as the only pathogen. Strains of the three species were tested by two widely used biochemical identification methods. A. turicensis was easily identifiable by both these methods. We conclude that these ALOs are not infrequent pathogens and are found in a wide range of human infections. At least A. turicensis is easily identifiable by clinical diagnostic laboratories.

Actinomyces↗
PubMed1998

Resistance of staphylococci in The Netherlands: surveillance by an electronic network during 1989-1995.

An electronic surveillance network for monitoring antibiotic resistance in The Netherlands has been in operation since 1989. Seven public health laboratories participate and the system covers about 25% of all bacteriological determinations in The Netherlands. This paper reports the results of staphylococci isolated in the period 1989-1995. About 0.3% of the Staphylococcus aureus isolates in the study period were resistant to methicillin. This low percentage may be due to the restrictive use of antibiotics and to strict isolation measures aimed at eradicating methicillin-resistant S. aureus. Low frequencies of resistance among methicillin-resistant S. aureus were found for vancomycin (0%), chloramphenicol (11%), cotrimoxazole (11%), mupirocin (3% low-level resistance) and fusidic acid (7%). Twenty-one percent of the coagulase-negative staphylococci were resistant to methicillin. Low frequencies of resistance among these methicillin-resistant coagulase-negative staphylococci were those to vancomycin (0.4%), nitrofurantoin (2%), doxycycline (20%) and amikacin (20%). Coagulase-negative staphylococci from cerebrospinal fluid, blood and skin were less often resistant to quinolones than isolates from respiratory tract, faeces and urine. A significant increase in resistance of coagulase-negative staphylococci to methicillin, erythromycin, gentamicin and ciprofloxacin was observed in the investigated period but the resistance to doxycycline and co-trimoxazole decreased in the last few years. To confirm the determination of methicillin resistance and coagulase production, a PCR method was developed which detects both the mecA and the coagulase gene. The results of the PCR method correlated well with the methicillin MIC as determined by an agar-dilution method.

Anti-Bacterial Agents↗
PubMed1997

Pitfalls and fallacies of cat scratch disease serology: evaluation of Bartonella henselae-based indirect fluorescence assay and enzyme-linked immunoassay.

The diagnostic value of the detection of immunoglobulin G (IgG) and IgM by Bartonella henselae-based indirect fluorescence assay (IFA) and enzyme-linked immunoassay (EIA) for the diagnosis of cat scratch disease (CSD) was evaluated. The IFA was performed either with B. henselae that was cocultivated for a few hours with Vero cells or with noncocultivated B. henselae as the antigen. Additionally, the performance of a Bartonella PCR hybridization assay based on the 16S rRNA gene was determined and compared with those of the serologic assays. The study group consisted of 45 patients suspected of suffering from CSD by fulfilling one or more of the classical criteria. The specificities of the immunoassays were set at > or = 95% by analysis of sera from 60 healthy blood donors. It is shown that the sensitivities of the IgG assays are very low (40.9% for the IFA with noncocultivated B. henselae as antigen) and that those of the IgM assays are higher (71.4% for the EIA) for patients who fulfilled two or more criteria for CSD. The IgM EIA showed the highest sensitivity: 71.4% in patients with two or more criteria for CSD and 80.6% for patients with a positive Bartonella PCR result. The results indicate that the specificities of both IFA and EIA IgG serologies and the sensitivity of the IFA IgM serology need to be improved. The PCR hybridization assay showed a sensitivity of 86.4% for patients who fulfilled two or more criteria for CSD and 100% for seven patients who fulfilled three or more criteria. The kinetics of IgG and IgM antibody production were studied in 18 patients with CSD on the basis of a positive B. henselae IFA IgM serology. The results indicate that there is no standard course of anti-B. henselae IgG and IgM production in patients with CSD, because some patients produced high levels of both IgG and IgM, others produced only high levels of IgM, and a few patients produced only low levels of antibodies.

Antibodies, Bacterial↗
PubMed1993

[Intravenously-administered immunoglobulins as first-choice agent in juvenile dermatomyositis].

Dermatomyositis is an acquired disease characterised by symmetric predominantly proximal muscle weakness of the arms and legs, and misery. It may be associated with myalgia and there is often a characteristic rash. The mainstay of therapy is corticosteroids. Recently efficacy of intravenous immunoglobulin (IVIg) in chronic refractory dermatomyositis was reported. Because corticosteroids can cause serious side effects, we treated a seven-year-old girl suffering from dermatomyositis with IVIg as initial therapy. After two courses of IVIg infusions at a dose of 0.4 g/kg/day for five consecutive days, the patient made a rapid and complete recovery. This case shows that IVIg may be effective as initial therapy in patients with dermatomyositis. Whether IVIg is really a better treatment than corticosteroids should be investigated in a randomised study.

Biopsy↗
PubMed1988

Development of an antibody-capture IgM-enzyme-linked immunosorbent assay for diagnosis of acute Epstein-Barr virus infections.

An anti-EBV IgM-ELISA was developed using the antibody-capture principle, to be used for the diagnosis of acute infectious mononucleosis (IM). The test was based on anti-human IgM-coated microtiter plates; nuclei of EBV producer cells were used for antigen; conjugate was prepared by labeling sheep anti-EBV IgG with horseradish peroxidase. The specificity of the anti-EBV IgM-ELISA was studied with a panel of sera from acute infections with hepatitis A virus, rubella virus, Toxoplasma gondii and cytomegalovirus, and sera positive for rheumatoid factors, positive for antinuclear antibodies, as well as with sera from normal blood donors and pregnant women. Specificity in these panels was 98.4%. In a clinical study with 449 sera from patients with IM-like symptoms, 109 of 109 confirmed patients were detected by the anti-EBV IgM-ELISA. Specificity of the anti-EBV IgM-ELISA in this clinical study was 99.7%. The anti-EBV IgM-ELISA detected several acute EBV patients who had negative heterophile antibody titers.

Acute Disease↗
PubMed1984

Immunological investigations in aplastic anemia patients.

In 53 patients with aplastic anemia (AA) a number of parameters concerning immune responsiveness were analyzed. Severe monocytopenia and B-lymphocytopenia was detected in most patients, especially in those with diffuse lymphocyte infiltration in the bone marrow. T-inducer (OKT4)/T-suppressor (OKT8) ratios were normal. The mean IgG level was significantly decreased. The frequency of specific antibodies to common viruses was comparable to that of healthy donors except for cytomegalovirus to which antibodies were less frequently found. The responding capacity in MLC was normal but patients' lymphocytes were often less stimulating than control lymphocytes. Radioresistant suppressor cells were found in 1 patient. In vitro lymphocyte reactivity to mitogens and antigens was severely impaired, related to the numbers of monocytes present. When allogeneic monocytes were added, mitogen responses could be restored.

Anemia, Aplastic↗
PubMed1984

LDH analysis of human thymocytes and thymocyte subsets.

The lactate dehydrogenase (LDH) isoenzyme pattern (expressed as the B:A subunit ratio) and two enzymes of the purine metabolism adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) (expressed as the ADA/PNP ratio) were studied in human prenatal thymocytes, in subsets of human infant thymocytes, and in peripheral T lymphocytes. Prothymocytes were enriched by E rosette depletion, cortical thymocytes were enriched with a monoclonal antibody rosette technique using OKT6, and medullary thymocytes were enriched either with a monoclonal antibody rosette technique using OKT3 or with complement-mediated cytolysis using normal fresh rabbit serum. Peripheral T lymphocytes were isolated from normal adult peripheral blood by E rosette sedimentation. Prenatal thymocytes had the lowest B:A ratio. In the infant thymuses, prothymocytes had a lower B:A ratio (0.99 +/- 0.10) than the cortical thymocytes (1.04 +/- 0.08). The medullary thymocytes obtained either by OKT3 selection or normal rabbit serum cytotoxic treatment had higher B:A ratios (1.30 +/- 0.15 and 1.42 +/- 0.17, respectively). The highest B:A ratio is found in peripheral T lymphocytes (2.07 +/- 0.28) together with the lowest ADA/PNP ratio (0.50 +/- 0.07). The B:A ratios are paralleled by a progressive decrease in the ADA/PNP ratio. These findings indicate that during intrathymic T cell development, important changes occur not only in the activities of the enzymes of the purine metabolism but also in the distribution of the LDH isoenzymes.

Adenosine Deaminase↗
PubMed1983

Analysis of variability in lymphocyte transformation tests.

To estimate the importance of a number of variables influencing the results of the lymphocyte transformation test (LTT), we analysed retrospectively the results of 250 LTTs on healthy control lymphocytes tested during the last 5 years as part of the routine LTT program. Prospectively, frozen cells from 3 donors were tested together on 5 different occasions. Differences in day-to-day test conditions had only minor influence. The influence of biologic variables was also negligible. The 2 most important factors were intrinsic cell differences, most probably due to damage during freezing, and genetic influences. To demonstrate minor differences between donors or between bleeding dates, repeated testing is necessary to eliminate these intrinsic variables and to allow statistical analysis.

Freezing↗
PubMed1982

Anti-thymocyte globulin treatment for aplastic anemia.

20 patients with severe aplastic anemia were treated with anti-thymocyte globulin (ATG), 6 of them in combination with haplo-identical bone marrow. 7 patients (35%) showed a good clinical response within 6 months; they were off transfusions and had greater than or equal to 0.8 x 10(9)/l neutrophils. ATG had the greatest effect on red-cell production and the least on platelet production. The hematological recovery with ATG could not be predicted from the bone-marrow histology, CFU-c growth, or clinical data. However, patients with strong HLA antibodies seemed to respond more often. The actuarial survival was 55% at 5 years. Under intensive supportive care, even 7 out of 12 non-responders were alive after 1 year. ATG appears to be a useful form of therapy for patients with severe aplastic anemia who are not candidates for bone-marrow transplantation.

Adolescent↗
PubMed1982

Group-specific auto-immune antibodies directed to granulocytes as a cause of chronic benign neutropenia in infants.

Chronic benign neutropenia of infancy is a disease which develops a few months after birth and which is characterized by a severe selective neutropenia, accompanied by benign but persisting infections. The cause of the disease is still unknown. The sera from 5 such patients were tested for the presence of granulocyte antibodies as a possible cause of the disease. For the detection of these antibodies immunofluorescence, agglutination and granulocytotoxicity were used. All sera contained antibodies which reacted both with the neutrophils of one or both parents of the patient and a part of a panel of unrelated donors. From the reaction patterns against the panel we could identify the specificity of three sera. Two sera were directed to the neutrophil-specific antigen NA2, and the third one reacted with a hitherto not yet recognized neutrophil-specific alloantigen which we called NE1. In 4 patients we could confirm the autoimmune character of the disease by demonstrating the antibody on the patients' own granulocytes. These results suggest that autoimmunity may be the cause of many cases of benign infantile neutropenia.

Agglutination Tests↗
PubMed1981

Anti-thymocyte globulin (ATG) can eliminate platelet refractoriness.

Of the 14 patients with aplastic anaemia treated in our hospital with anti-thymocyte globulin (ATG), four were refractory to random platelets before therapy due to the presence of leucocyte antibodies. In contrast to the ten nonrefractory patients in whom no success was obtained, three of the four refractory patients showed haematological improvement after ATG. Additionally, two patients could be substituted again with random platelets. The other two hardly needed platelet-transfusions after ATG, and they were given HLA-compatible platelets. To determine the degree of immunosuppression, these four patients were tested for the presence of antibodies against leucocytes and two endemic viruses, i.e., mumps and rubella virus. Before ATG, all sera reacted with almost the whole leucocyte testpanel. After treatment, the leucocyte antibodies disappeared completely in three patients. In one patient there was no dramatic change. In all patients, however, the antibody-titre against the mumps and rubella viruses remained constant and there was only a slight decrease in total IgG content in the three "suppressed" patients. We conclude that it might be worthwhile to study systematically the selective immuno-suppressive effect of ATG.

Adult↗
PubMed1980

T lymphocyte function in hairy cell leukaemia.

The high incidence of infections characteristic of impaired cell-mediated immunity in patients with hairy cell leukemia led us to study T lymphocyte function in sixteen patients with the lymphocyte transformation test. All patients showed imparied responses to mitogens, attributable to one or more of the following causes: dilution of responsive T cells by inert hairy cells, shortage of monocytes to give adequate interaction with the T cells and a significant decrease in the number of T cells with Fcmu receptors proportional to the percentage of hairy cells in the peripheral blood. The response to antigens was severely depressed; PPD was one of the few antigens that induced positive reactions in half the cases. We conclude that in patients with hairy cell leukaemia, T lymphocyte function, as tested in a proliferative assay, is severely impaired and that this may contribute to the deficient resistance to infection.

Adult↗
PubMed1979

NE1: a new neutrophil specific antigen.

The sera of three children with chronic benign neutropenia, due to anti-neutrophil antibodies, were studied with respect to their antibody specificity. This was done by screening the sera against a panel of leukocyte donors in the EDTA micro-agglutination test and in the indirect fluorescence test. Two of the sera contained antibodies against the known neutrophil-specific antigen NA2. The third serum was directed against a new neutrophil-specific antigen. Genetic analysis showed no correlation between this antigen and the already known neutrophil-specific antigens: 9A, NA1, NA2, NB1, and NC1. In the Dutch population the frequency of the new antigen, tentatively called NE1, is 23%, which gives a gene frequency of 0.12.

Agglutination Tests↗
PubMedDate not supplied

Occurrence of extended-spectrum betalactamases (ESBL) in Dutch hospitals.

The prevalence of ESBL was determined among isolates of Escherichia coli (n = 571) and Klebsiella spp. (n = 196) collected during a 1-week study period in 8 university and 3 large regional laboratories all over the Netherlands. 18 isolates were positive for at least one of the screening tests used, i.e., VITEK-ESBL, E-test ESBL and MIC ratio of ceftazidime/ceftazidime-clavulanic acid, cefotaxime/cefotaxime-clavulanic acid. In 5 of these 18 putative ESBLs no betalactamase production was detectable. A TEM type was found in three E. coli and two Klebsiella spp. An SHV type was present in five Klebsiella spp. In one E. coli and one Klebsiella pneumoniae both enzymes were present. In one Klebsiella oxytoca neither of the two enzymes was present. Using PCR for both ESBL TEM and ESBL SHV, an SHV ESBL was found in one E. coli and four Klebsiella isolates. The mutations at position 238 and 240 were already described. In one E. coli isolate a TEM ESBL was found with three mutations, at position 21, 164 and 265. These mutations were already described in other ESBLs but not in this combination suggesting a new TEM ESBL. The overall prevalence of ESBL producing E. coli and Klebsiella spp. was less than 1% (6 out of 767).

Anti-Bacterial Agents↗