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Biomedical subjects

H Krauss

Publications and source records attributed to H Krauss.

At least 37 records · Page 2Linked to original sources
PubMed1996

Primary culture of Borrelia burgdorferi from Ixodes ricinus ticks.

A total of 971 Ixodes (I.) ricinus ticks field-collected in May and June 1993 and 1994 in two different geographic regions (Middle Hesse and Lower Saxony) were examined for the presence of Lyme borreliosis spirochetes (Borrelia burgdorferi sensu lato) by primary culture using nonselective and selective BSK II medium. Modifications of BSK II medium with varying concentrations of bovine serum albumin and with rabbit serum being replaced by horse serum were examined for their ability to support growth of borreliae from ticks. Spirochetes were isolated from 17.8% each of female and male I. ricinus from Lower Saxony. Isolation rates from female and male I. ricinus originating from Middle Hesse were 13.5% and 19.6%, respectively. In comparison to nonselective BSK II medium the isolation rate of borreliae from the tick midgut was increased significantly (35%) by additional culture in selective BSK II medium. Most spirochetal isolates (85%) were detected within three weeks of incubation. Compared to isolation in standard BSK II medium, reduction of bovine serum albumin by 50% did not diminish the isolation rate of borreliae from ticks. Spirochetal isolates were identified as Borrelia burgdorferi sensu lato by PCR using a primer set based on ribosomal DNA sequences to amplify the variable spacer region between two conserved structures, the 3'end of the 5S rRNA and the 5'end of the 23S rRNA.

Animals↗
PubMed1996

Monoclonal antibody based differentiation of Coxiella burnetii isolates.

Isolates of Coxiella burnetii from different geographic regions in Europe, USA, Japan and Africa were compared in their binding properties to the monoclonal antibody (MoAb) 1/4/H directed against the lipopolysaccharide (LPS) of C. burnetii strain Priscilla. Immunoblot analysis and enzyme-linked immunosorbent assay (ELISA) revealed different binding patterns of C. burnetii isolates under study. Most of the isolates tested did react with MoAb 1/4/H. Only four of 20 groups of isolates and one isolate of an otherwise positively reacting group did not react with MoAb 1/4/H. The results indicate a significant variation of LPS structure of the C. burnetii isolates studied.

Animals↗
PubMed1995

Sequencing and linkage analysis of a Coxiella burnetii 2.1 kb NotI fragment.

Most of the Coxiella burnetii isolates (72 of 80) available in our institute share a 2.1 kb NotI fragment. Sequence analysis revealed two incomplete open reading frames (ORF) for putative genes hemA and bcR coding for glutamyl-tRNA-reductase and bicyclomycin resistance protein, respectively. Upon completing the ORF for the hemA gene by sequencing the adjacent NotI/EcoRI fragment a third ORF for the putative prfA gene was determined coding for release factor 1, an enzyme catalysing the last step in protein biosynthesis.

Aldehyde Oxidoreductases↗
PubMed1994

Analysis of the entire nucleotide sequence of the cryptic plasmid QpH1 from Coxiella burnetti.

The complete plasmid QpH1 from Coxiella burnetti, isolate 'Nine Mile', phase I, was cloned as NotI fragment with a size of 37329 bp. The entire plasmid was sequenced by the chain termination method after EcoRI subcloning. 37 open reading frames coding for polypeptides larger than 100 amino acid residues were determined. The predicted polypeptide products of the open reading frames were compared by computer analysis with reported protein sequences. Homologies of predicted polypeptide products to analogous proteins are described.

Amino Acids↗
PubMed1994

The 16S/23S ribosomal spacer region of Coxiella burnetti.

The 16S/23S spacer region of Coxiella burnetti isolate Nine Nile, phase 1, was sequenced. Sequence analysis revealed two tRNA coding regions for tRNA(Ile) and tRNA(Ala). DNA sequence alignment demonstrated significant homology with tRNA species from Pseudomonas aeruginosa and Rhodobacter sphaeroides, respectively. The non-coding tRNA spacer region was unique to Coxiella burnetti, based on database alignment.

Cloning, Molecular↗
PubMed1994

Comparison of dark-field microscopy, culture, and polymerase chain reaction (PCR) for detection of Borrelia burgdorferi in field-collected Ixodes ricinus ticks.

In a study based on 100 field-collected female Ixodes (I.) ricinus ticks from the surroundings of Giessen, dark-field microscopy (DFM), culture, and PCR were compared as procedures for detecting Lyme borreliosis spirochetes in ticks. By DFM, 16 ticks were found to be infected with spirochetes. From the midgut of 18 ticks (including 14 microscopically positive specimens), spirochetes were cultured in BSK II medium and in BSK II medium supplemented with either co-trimoxazole (500 micrograms/ml) or 5-fluorouracil and kanamycin (200 micrograms/ml and 8 micrograms/ml). Using these selective media, the isolation rate was increased by 50% compared to BSK II medium without additives. Midgut homogenates of 22 ticks (including 13 ticks positive by culture and 12 microscopically positive ticks) were found to contain Borrelia (B.) burgdorferi-specific DNA by PCR using a primer set based on sequences of the flagellin gene of B. burgdorferi.

Animals↗
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

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

Rabbit hemorrhagic disease: a review with special reference to its epizootiology.

Rabbit hemorrhagic disease (RHD) is a relatively new and economically important viral disease of wild and domestic rabbits and hares. Characteristic lesions are abundant hemorrhages in many organs, e.g. trachea, lung, liver, kidney, spleen, peritoneum and pleura. In the past few years epidemic outbreaks of this disease have been observed worldwide. The aim of this paper is to review the literature on this disease with special reference to its epizootiology.

Animals↗
PubMed1993

Studies of the prevalence of Coxiella burnetii, the agent of Q fever, in the foothills of the southern Bavarian Forest, Germany.

In studies carried out in 1991 in the foothills of the southern part of the Bavarian Forest, in the district of Freyung/Grafenau, ticks and small mammals were collected and examined for the presence of Coxiella (C.) burnetii and sera of small mammals and cattle investigated for antibodies against this rickettsia. A total of 1716 imagines and nymphs of Ixodes ricinus were collected by flagging and 892 larvae and nymphs of the same tick species removed from small mammals. In addition to 1095 serum samples from cattle, 326 specimens of nine species of small terrestrian mammals were examined. Neither in ticks nor in rodents, C. burnetii was detected, however, in 17 of 21 localities, seropositive cattle were found. Altogether, 12% of all 1095 heads of cattle tested were seropositive for C. burnetii antibodies. These serological results indicated a wide dissemination of C. burnetii in cattle of the region investigated, but there was no indication of a natural focus. As in other areas of Europe, an independent natural cycle of the agent involving cattle only is assumed to occur in this region.

Animals↗
PubMed1993

[Effect of insulin on temperature and metabolic responses in rats during normothermia and hypothermia].

As shown in our previous study, hypothermia provokes a variety of hormonal changes including inhibition of insulin secretion and increase in blood serum glucagon level. According to Therminarias et al. the administration of exogenous insulin to dogs subjected to hypothermia causes a calorigenic effect by enhancing oxygen consumption and rising the intensity of shivering thermogenesis. The study was aimed at establishing whether exogenous insulin administered to rats subjected to brief hypothermia and having the shivering thermogenesis blocked by thiobutabarbital anesthesia can influence rectal temperature, the levels of some hormones and energy metabolism. The results obtained suggest that 1) insulin administration causes an increase in the energy charge potential (ECP) both in the liver and in skeletal muscle of the rat, indicating the domination of anabolic processes both in normothermic and hypothermic conditions, 2) there is a negative correlation between the levels of insulin and free fatty acids and the activity of isocitric dehydrogenase in rat liver mitochondria, and 3) the administration of insulin at a dose provoking metabolic response both in normothermic and hypothermic conditions was ineffective in provoking temperature response, indicating the existence of a functional dissociation between the various effects of the same dose of exogenous insulin.

Animals↗
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↗