Search PubMed⌕ Search

Biomedical subjects

D Thiele

Publications and source records attributed to D Thiele.

At least 37 records · Page 2Linked to original sources
PubMed1994

Monoclonal antibody based competitive ELISA for the detection of specific antibodies against Coxiella burnetii in sera from different animal species.

A competitive ELISA system for the detection of antibodies against Coxiella (C.) burnetii in cattle, sheep, goats, horses and humans is described. The ELISA is based on a biotinylated monoclonal antibody with specificity for C. burnetii lipopolysaccharide in combination with streptavidin peroxidase. For evaluation and statistical analysis, 413 sera from cattle, sheep, goats, horses and humans were tested in parallel in the indirect immunofluorescence test (IFT). Furthermore, a total of 448 bovine and human sera were also tested with an indirect ELISA and 47 sheep sera were investigated using the commercially available "Ridascreen AK EIA". Sensitivity and specificity values for the competitive ELISA described and determined with the aid of the indirect immunofluorescence test (IFT) as reference were: cattle, 88% and 89%; sheep, 100% and 93%, goat, 82% and 96%, horse 100% and 93%, and man 42% and 96%, respectively.

Animals↗
PubMed1994

Valvular endocarditis occurs as a part of a disseminated Coxiella burnetii infection in immunocompromised BALB/cJ (H-2d) mice infected with the nine mile isolate of C. burnetii.

BALB/cJ (H-2d) mice were injected intraperitoneally (ip) with cyclophosphamide 2 days after ip inoculation with Coxiella burnetii Nine Mile, phase I. Ten days after infection, disseminated microabscesses, granulomas, and microthrombi were observed in most organs, including spleen and liver, and in bone marrow. In addition, endocarditis of the atrioventricular and semilunar valves, characterized by macrophages and neutrophils, was present. At the same time, C. burnetii antigen was found in most organs and in cardiac valves, aorta, and pulmonary artery, mainly within macrophages, neutrophils, and endothelial cells. C. burnetii-specific IgG antibodies were detected 150 days after infection but not in the early phase of infection. Cardiac valves were devoid of C. burnetii antigen and without residual lesions at 150 days. These findings offer the possibility for further studies on the pathogenesis of C. burnetii-associated valvular endocarditis and show that acute strains of C. burnetii can cause endocarditis as a part of a disseminated infection in the immunocompromised host.

Animals↗
PubMed1994

Detection of Coxiella burnetii in cow's milk using the polymerase chain reaction (PCR).

A PCR approach (transposon PCR) with primers based on repetitive transposon-like sequences, which--depending on the isolate--were found at a minimum frequency of 19 on the C. burnetii genome, was established for the highly sensitive and specific detection of C. burnetii. This study describes the analytical detection of C. burnetii in milk, which requires a special preparation method prior to PCR. Because of the low level of C. burnetii particles in milk samples, template DNA was concentrated by a factor of 200, using cetyltrimethylammonium bromide as the precipitation reagent. Using this particular preparation method, even a single C. burnetii particle could be detected in 1 ml milk.

Animals↗
PubMed1994

[Detection of Chlamydia psittaci in vaginal discharge of cows: a necessary enlargement of bacteriologic diagnosis for the etiologic clarification of fertility disorders in the female cow].

Vaginal discharge from 119 dairy cows from 59 herds was examined bacteriologically, including application of the IDEIA Chlamydia test, to detect genus-specific chlamydial LPS-antigen. A putrid quality of specimens was closely correlated with isolation of Actinomyces pyogenes (p < 0.001). The IDEIA was positive for 39 of 65 (60.0%) non-putrid specimens and for 16 of 54 (29.6%) putrid specimens; a non-putrid quality of specimens was closely correlated with the detection of chlamydial antigen (p < 0.01). IDEIA-positive results were confirmed by a blocking-antibody assay and by polymerase chain reaction (PCR) using a set of primers based on the 16S rRNA sequences of Chlamydia psittaci. Chlamydia-positive non-putrid specimens generally yielded no other bacterial pathogens. The clinical history of repeat breeding and endometritis, as well as failure to isolate other bacterial pathogens on routinely used non-living media, were strongly suggestive of primary chlamydial involvement in these cases.

Animals↗
PubMed1993

Plasmid based differentiation and detection of Coxiella burnetii in clinical samples.

A "nested" PCR approach with primers based on conserved plasmid sequences was used for the highly sensitive and specific detection of Coxiella (C.) burnetii in clinical samples collected from cattle, dogs, cats and humans. Results were in good agreement with those obtained from Capture-ELISA and isolation of the organism in BGM cell culture. We also tested primers with sequences derived from genomic DNA and sequences based on 16S rRNA. In addition, we applied PCR for the differentiation of C. burnetii plasmid types from 28 isolates originating from the USA, Europe and South Africa. Reference isolates Nine Mile RSA493, Dugway 5J108-111 and all European isolates tested were recognized only by primers specific for the QpH1 plasmid. One isolate from a goat abortion in Namibia reacted identically to the reference isolate Priscilla Q177 bearing the QpRS plasmid. Reference isolate S Q217 with plasmid sequences integrated into the genome reacted with none of the plasmid-specific primer pairs.

Animals↗
PubMed1993

Polymorphism in DNA restriction patterns of Coxiella burnetii isolates investigated by pulsed field gel electrophoresis and image analysis.

Pulsed field gel electrophoresis was used for differentiation of Coxiella burnetii isolates derived from animals in Europe and one from Namibia. Previously published data on isolates from North America demonstrated four groups with distinct banding patterns. Fingerprints of prototype isolates as references confirmed four different cleavage patterns upon NotI restriction of total DNA as described. With isolates available at our institute five additional DNA banding patterns were obtained from European and one Namibian isolate after endonuclease restriction with NotI. To compare patterns from different electrophoretic runs more precisely an image analysis system was used.

Animals↗
PubMed1993

A sporulation gene in Coxiella burnetii?

During a search for conserved target sequences on the genome of Coxiella burnetii for a diagnostic PCR a NotI/EcoRV DNA fragment was cloned and sequenced from the isolate "Nine Mile", Phase I (sequence data are registered under accession number X70045 in data bases EMBL, GENEBANK and DDBJ). On this fragment we have found a sequence of 1741 base pairs which showed an exceptionally high homology (60% on the nucleic acid level and 49.6% on the amino acid level) to the sporulation gene "spoIIIE" of the gram-positive bacterium Bacillus subtilis. This is first evidence of the molecular basis for formation of spores in Coxiella burnetii which has been postulated in the literature by electron microscopic investigations.

Amino Acid Sequence↗
PubMed1992

Monoclonal antibody based capture ELISA/ELIFA for detection of Coxiella burnetii in clinical specimens.

A CAPTURE ELISA/ELIFA system based on monoclonal capture and biotinylated monoclonal detection antibody is described. The assay is fast, highly specific and detects a minimum dose of 2500 Coxiella (C.) burnetii particles. In contrast to the sophisticated and cumbersome isolation procedures, even non-specialized laboratories could use this assay system for investigating clinical samples of different origin for C. burnetii within a short period of time.

Antibodies, Monoclonal↗
PubMed1992

Immunoblot technique for Q fever (technical note).

Partially purified but unfixed C. burnetii cells were submitted to sodium dodecylsulfate polyacrylamide gel electrophoresis, Western blotted and used as antigens for evaluation of antibody responses against the agent in mice, cattle and humans. Increased specificity was achieved by using glutaraldehyde as additional blocking agent. Gels as well as membranes were subjected to laser densitometry and data analysed with an IBM personal computer. This technique offers the possibility to objectively quantify and document the results of immunoblotting.

Animals↗
PubMed1992

Evaluation of the polymerase chain reaction (PCR) for detection of Chlamydia psittaci in abortion material from ewes.

The polymerase chain reaction (PCR) was evaluated as a diagnostic tool for detection of Chlamydia (C.) psittaci in abortion material from 40 ewes. For this purpose, PCR results of 87 samples were compared with direct microscopic identification after chemical staining, cell culture isolation and a commercially available enzyme-linked immunosorbent assay (ELISA). The value for sensitivity as compared to cell culture was 97.7% whereas the specificity-value was calculated to be 84.1%.

Abortion, Veterinary↗
PubMed1992

Monoclonal antibody based capture ELISA/ELIFA for the detection of Chlamydia psittaci in veterinary clinical specimens.

A capture ELISA/ELIFA system based on monoclonal capture and biotinylated monoclonal detection antibody with specificity for an epitope on chlamydial lipopolysaccharide (LPS) is described. The assay is fast, specific and detects a minimum dose of approximately 2000 chlamydial particles (C. psittaci). Unlike other commercially available test kits, it comprises a proteinase K treatment to exclude non-specific binding of antibodies to Fc receptors. In contrast to the sophisticated and cumbersome isolation procedures, even non-specialized laboratories may use this assay system for the investigation of clinical samples of different origin for the presence of C. psittaci within a short period of time. Due to the genus specificity of the monoclonal antibody used C. trachomatis and C. pneumoniae can be detected as well.

Animals↗
PubMed1992

Immunoblot analysis of IgG subclass antibody response against Coxiella burnetii in Balb/c mice.

Balb/c mice were inoculated with live or inactivated organisms of Coxiella burnetii, strain Nine Mile, phase I. Sera collected after different time intervals were subjected to immunoblot analysis and results compared with ELISA values. Immunoblots were performed with different horseradish peroxidase labelled conjugates (goat anti-mouse IgG1, IgG2a, IgG2b, IgG3) and results monitored and analysed by laser densitometry. ELISA analysis was performed using the same peroxidase labelled goat anti-mouse subclass antibody conjugates. In addition, goat anti-mouse IgG(H+L), IgG(H), IgM, and IgA conjugates were used for ELISA tests.

Animals↗
PubMed1991

The effect of various contexts of stress on the mouse spleen lymphocytes and macrophage co-stimulatory activity.

Mice stressed daily by brief cold water immersions for 1, 8 or 14 days showed changes in immune system function which were dependent on the number of mice per cage, frequency of stress exposures and total number of stress exposures. Changed percentages of spleen B and CD4, but not of CD8 cells were determined when the mice were stressed either once or twice daily. With CD4 cells, increased percentages were seen after stress once daily but a decreased percentage was seen after stress twice daily. Furthermore, the Concanavalin A-stimulated spleen cell mitogenesis was decreased after 1 day of stress in mice stressed once daily as opposed to after 8 and 14 days of stress in mice stressed twice daily. After 14 days of stress, the lipopolysaccharide stimulated mitogenesis was increased if the mice were stressed once daily but decreased if the mice were stressed twice daily. With two mice per cage, we observed a decreased spleen cell mitogenesis after 14 days of stress. With four mice per cage, the spleen cell mitogenesis was decreased after 8 and 14 days of stress. If spleen cell populations from mice stressed twice daily for 8 days were depleted of macrophages and CD4 or CD8 cells, the effect of stress on the mitogenesis was removed from the CD8 cells. Spleen cells of mice stressed for 14 days showed a decreased mitogenesis when depleted of adherent cells and reconstituted with adherent cells from control mice. Furthermore, the adherent cells from these mice had decreased ability to support mitogenesis of adherent cell-depleted spleen cells from control mice as well as a decreased IL-1 production.

Animals↗
PubMed1991

Characterization of a murine IgG3 monoclonal antibody against Chlamydia-specific lipopolysaccharide and its purification by affinity chromatography on IgG Fc-receptors from Streptococcus dysgalactiae.

Purification of a murine IgG3 monoclonal antibody (Mab 22) directed against an epitope of Chlamydia-specific lipopolysaccharide by affinity chromatography on recently described solid phase IgG Fc-receptors from Streptococcus dysgalactiae is reported. SDS-PAGE studies revealed the purity of the eluted antibody. The purified Mab 22 was characterized by determination of class, subclass and light chain-type, and by dot tests and immunoblot analysis.

Animals↗
PubMed1991

[The problems of vaccination against chlamydial abortion in sheep].

Different vaccines used against chlamydial abortion in sheep are described. Problems associated with insufficient immunity after vaccination are discussed. Reasons for failure of certain vaccine preparations are addressed. Finally new developments in vaccine production are introduced which might be useful in solving problems still existing in the prevention of chlamydial abortion in sheep by vaccination.

Abortion, Veterinary↗
PubMed1990

The technique of polymerase chain reaction--a new diagnostic tool in microbiology and other scientific fields (review).

The polymerase chain reaction, a method of so far unknown sensitivity and specificity, is about to become an important diagnostic tool in microbiology. Practically even a single bacterium, virus particle, or parasite can be detected by it. Furthermore, this technique has been used with highly promising results in other scientific fields like genetics, forensic medicine and archeology. This article reviews technical aspects and variations of this new technique.

Animals↗