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I Greiser-Wilke

Publications and source records attributed to I Greiser-Wilke.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Emergence of "new" viral zoonoses].

In the last two to three decades a significant increase of viral zoonotic infections was observed. These zoonoses are not only newly (or previously unrecognized) emerging diseases, but also due to the reappearance of diseases thought to have been defeated (re-emerging diseases). "New" viral diseases can arise when viruses broaden their host-range (monkey poxvirus; equine morbillivirus), or can be a consequence of intrinsic properties of the virus itself, such as high mutation rates (influenza A virus). Most new or reemerging viral zoonoses are due to infections with hemorrhagic viruses. Many of them are transmitted by insects (arboviruses, e.g. yellow fever virus) or by rodents (e.g. Hanta viruses), others by contact with patients and nosocomial infections (e.g. Ebola virus). The emergence and increase of these diseases are a consequence of anthropogenic environmental changes, such as distortions of the ecological balance and changes in agriculture. In addition, the uncontrolled growth of the cities in tropical and subtropical regions without improvement of the public health measures and the increasing international animal trade and travel also favour the spread and recurrence of these diseases.

Animals↗
PubMed1998

Serological cross-reactivity between Brucella abortus and yersinia enterocolitica 0:9: IV. Evaluation of the M- and C-epitope antibody response for the specific detection of B. abortus infections.

Smooth lipopolysaccharides (SLPS) from Brucella abortus contain A-epitopes against which the majority of serum antibodies are directed during infections. SLPS from Yersinia enterocolitica 0:9 possesses identical epitopes, which are the cause for serological cross-reactivity. All Brucella spp. possess M- and C-epitopes which are not present in Y. enterocolitica 0:9. In order to examine the usefulness of these M- and C-epitopes for discriminatory serological testing, a panel of sera were used in this study, comprising sera from Y. enterocolitica 0:9-infected heifers, sera from B. abortus-infected cattle of comparable strength in the serological brucellosis tests to the sera from Y. enterocolitica 0:9-infected heifers, sera from B. abortus-infected bovines with strong serological reactions and sera from animals free from B. abortus or Y. enterocolitica infections. These sera were tested in blocking ELISAs with seven M- and one C-epitope-specific monoclonal antibodies in combination with SLPS from B. melitensis M16 high in M-epitopes as antigen. Strong B. abortus sera inhibited most strongly, while negative sera showed no or little inhibition. Sera with weak or intermediate titres blocked to a lower extent. Unexpectedly, the sera from Y. enterocolitica 0:9-infected heifers showed inhibition behaviour virtually identical to the comparable sera from B. abortus infected animals. Absorbing out of the A-epitope specific serum antibodies with either Y. enterocolitica 0:9 SLPS or with Y. enterocolitica 0:9 bacteria, indicated the presence of M- or C-epitope-specific serum antibodies in some sera from B. abortus-infected cattle but not in the sera from Y. enterocolitica 0:9-infected animals. These results demonstrate that the M- or C-epitope-specific antibody response in sera from B. abortus infected cattle is only of limited value for the serological discrimination between B. abortus and Y. enterocolitica 0:9 infections.

Animals↗
PubMed1998

Experimental induction of mucosal disease: consequences of superinfection of persistently infected cattle with different strains of cytopathogenic bovine viral diarrhea virus.

Mucosal disease (MD) can be induced in cattle persistently infected with noncytopathogenic bovine viral diarrhea virus (ncp BVD virus) by superinfecting them with antigenically related cytopathogenic (cp) BVD virus strains. While some of these animals succumb to early onset MD after 2 to 3 weeks post infectionem (p.i.), others only react by producing neutralizing antibodies against the cp BVD virus strain and may develop late onset MD after longer incubation periods. The aim of this study was to determine if an increasing degree of antigenic homology between the ncp and the superinfecting cp BVD virus strains as determined by their comparative reactivity with E2 glycoprotein specific monoclonal antibodies (mabs) increases the probability of inducing early or late onset MD, respectively. For this, each two of eight clinically healthy animals from the same herd and persistently infected with the same ncp BVD viruses were superinfected with four different cp BVD virus strains. As only two of these animals developed late onset MD, one animal from a different herd that developed early onset MD was included in the study. Besides clinical observation and testing for antibody production, virus isolation and characterization of the cp BVD virus isolates were performed. The results indicate that antigenic similarity as determined by comparative mab analysis alone is not sufficient to allow prediction of the outcome of the disease.

Amino Acid Sequence↗
PubMed1998

Application of a computer program for genetic typing of classical swine fever virus isolates from Germany.

The commercial software program HLA SequiTyper (Amersham Pharmacia Biotech), designed originally for human leukocyte antigen typing, was adapted for rapid typing of classical swine fever (CSF) virus isolates. The program compares new sequence data with those stored in a database file and calculates the most probable assignment. For generating the CSF virus sequence database, 150 bp of the 5' nontranslated genomic region (5'-NTR) from 88 German classical swine fever virus isolates from outbreaks between 1984 and 1997 were solid-phase sequenced directly after RT-PCR amplification. Sequence alignments showed that they all belonged to the previously defined genetic group 2. Within this group, six different subgroups could be distinguished, and were designated according to the geographic location where they are either still endemic or where they appeared most commonly. The advantage of using the HLA SequiTyper program is that it reads directly the sequence files as generated by the ALF sequencer (Amersham Pharmacia Biotech), making any manipulations unnecessary. In addition, a constant quality control of the raw sequence data can be achieved, as more than one sequence from the same isolate can be evaluated at once. Using this approach, new CSF isolates can be typed within 2 days.

Animals↗
PubMed1998

[Cytopathogenic bovine viral diarrhea viruses induce apoptosis in bovine cell cultures].

The pestivirus bovine viral diarrhea (BVD) virus is the causative agent of Mucosal Disease (MD) of cattle. From persistently infected animals, only the non-cytopathogenic biotype BVD virus can be isolated. Cattle succumbing to MD additionally harbour cytopathogenic BVD virus. While cp BVD virus isolates induce a cytopathic effect (cpe) in susceptible monolayer cell cultures, infection with ncp BVD virus isolates has no visible effect. The purpose of this study was to investigate the correlation between cpe and apoptosis.

Animals↗
PubMed1998

[Clinical-virologic course after superinfection of persistently infected cattle with cytopathogenic bovine viral diarrhea virus strains].

Vaccination with live cytopathogenic (cp) bovine viral diarrhoea virus (BVDV) is often used for control of this disease. In animals which are persistently infected with noncytopathogenic (ncp) BVDV this can lead to the outbreak of mucosal disease (MD). To simulate vaccination of such animals and to monitor the clinical-virological course after superinfection, nine clinically healthy calves which were persistently viremic were superinfected with different cp BVDV strains. One animal succumbed to early onset MD within three weeks after superinfection. During the observation period of 18 months four animals developed severe clinical signs. While two animals developed late onset MD, the other two had to be euthanized due to clinical signs which could not be related to the superinfecting BVDV. These results indicated that after superinfection or vaccination of persistently infected calves with cp BVDV the probability of developing early and/or late onset MD is significantly increased. The risks arising from uncritical vaccination of herds with unknown virological status in relation with the control of BVDV conforming to the actual official guidelines are discussed.

Animals↗
PubMed1998

[Apoptosis in virus infections of animals: a survey].

Cell death can be the consequence of different mechanisms. While necrosis always affects groups of cells and is linked to inflammation of the corresponding tissue, decay due to senescence is known as programmed or physiologic cell death. It affects single cells and is correlated with characteristic morphological and biochemical changes. These characteristic changes can also occur after induction of cell death before natural senescence and is then termed apoptosis. Apoptosis also plays an important role in the pathogenesis of viral infections, as viruses can either induce or inhibit cell death.

Animals↗
PubMed1997

The development of early vs. late onset mucosal disease is a consequence of two different pathogenic mechanisms.

Bovine viral diarrhea (BVD) virus is the causative agent of fatal mucosal disease (MD) of cattle. Experimental induction of MD can be achieved by superinfection of calves persistently viremic with a noncytopathic (ncp) BVD virus using an antigenically similar cytopathic (cp) BVD virus. Here we describe the characterisation of BVD viruses isolated from three cases of experimentally induced MD. One animal developed clinical symptoms two weeks after superinfection (early onset MD), while the onset of disease in the other two cases occurred with a delay of months (late onset MD). Antigenic characterisation of the viruses was performed using a panel of monoclonal antibodies against the E2 glycoprotein. For genetic analysis, RT-PCR was applied to amplify specific insertions and duplications in the NS2-3 genomic region of the cp BVD viruses. In addition, these amplicons and fragments of the viral E2 genes were sequenced. The results showed that in the case of early onset MD the cp BVD virus isolated after begin of disease was identical to the one used for superinfection. In contrast, the cp BVD viruses isolated from the two animals with late onset MD were obviously the result of genetic recombinations between the persistent ncp and the superinfecting cp BVD viruses. We conclude that early and late onset MD are the consequence of different pathogenic mechanisms.

Amino Acid Sequence↗
PubMed1997

Organ and tissue distribution of the antigen of the cytopathogenic bovine virus diarrhea virus in the early and advanced phase of experimental mucosal disease.

To study the development of lesions in mucosal disease, the spread of cytopathogenic (cp) bovine virus diarrhea virus (BVDV) to different organs was examined in relation to the time post inoculation (pi). Mucosal disease was induced in 15 persistently viremic cattle from two herds by intranasal inoculation with antigenically similar cp BVDV strain. This strain reacted with one additional monoclonal antibody when compared to the corresponding herd-specific non cytopathogenic (ncp) isolate. Twelve cattle were euthanized at days 3, 5, 7, 9 and 13 pi in the early phase before they developed clinical signs of mucosal disease, three in the advanced phase when they were moribund and three served as controls. Antigen of the cp BVDV strains was selectively detected in tissue sections by immunohistochemistry. In the early phase, varying amounts cp BVDV were present most consistently in tonsils, lymph nodes, Peyer's patches and lymphoid nodules in the large intestine. In the lymphoid tissues, first a few cells in single lymphoid follicles, then groups of lymphoid follicles contained antigen. In intestinal epithelium, cp BVDV antigen was found focally in the early phase of mucosal disease. Its diffuse distribution in the late phase corresponded with clinical signs of diarrhea.

Animals↗
PubMed1997

Analysis of the haemagglutinin gene of current wild-type canine distemper virus isolates from Germany.

The haemagglutinin (H) gene sequences from three wild-type canine distemper viruses (CDV) isolated during 1994-1995 were sequenced to determine whether contemporary strains had undergone significant genetic changes relative to the currently used vaccine strains. The new isolates were closely related to each other (> 99%) and displayed about 90-91% sequence homology to the Onderstepoort and Convac vaccine strains. There were one to four additional potential glycosylation sites compared to the vaccine strains which were also present in a German dog CDV isolate dating from 1990. However, only a very slight reduction in neutralizing titre against the new isolates was found when compared with the Onderstepoort and Rockborn vaccine strains. Cysteine and proline residues were well conserved indicating a conserved three dimensional structure for the protein. By phylogenetic analysis the recent isolates showed a narrow clustering close to the previous canine isolates indicating a linear pattern of evolutionary changes. A comparison with published CDV H gene sequences suggested the presence of different lineages of CDV on a global scale and possible cocirculation of more than one genotype of CDV.

Amino Acid Sequence↗
PubMed1995

Identification of cell membrane proteins linked to susceptibility to bovine viral diarrhoea virus infection.

Three monoclonal antibodies directed against cell surface molecules of bovine cells inhibited subsequent infections with bovine viral diarrhoea virus (BVDV). They specifically blocked the infectivity of three non-cytopathogenic and three cytopathogenic BVDV strains. These results showed that an important mechanism for virus uptake was inhibited. The ligand of the monoclonal antibody BVD/CA 17, which blocked infectivity most efficiently, was found on leukocytes from a wide range of domestic and wild even-toed ungulates using flow cytometric analysis. In contrast, the monoclonal antibodies BVD/CA 26 and BVD/CA 27 appeared to be specific for bovine cells. Immunoprecipitation of labelled bovine cell surface proteins showed that the three monoclonal antibodies bound to proteins with identical relative molecular masses (M(r)). Proteins of an apparent M(r) of 93 K and 60 K were precipitated from lysates of fetal bovine kidney cells irrespectively of the MAbs used.

Animals↗
PubMed1995

Spot synthesis of overlapping peptides on paper membrane supports enables the identification of linear monoclonal antibody binding determinants on morbillivirus phosphoproteins.

In order to map antigenic domains on the P-protein of morbillivirus, a series of overlapping peptides, representing the P-protein sequences of phocid distemper virus strain 2558/Han88 and canine distemper virus strain Onderstepoort, were synthesized on a paper support by the spot-technique. The reactivity of six monoclonal antibodies with the peptides was tested in an enzyme immunoassay and compared to their reactivity in Western blots and in an ELISA using detergent extracts from virus-infected cells. Three linear determinants could be localized on the P-protein. Two antibody-binding sites were delineated within the C-terminal (between amino acids 307-322 and 382-400, respectively), and a third one was located on the N-terminal part (amino acids 13-31) of the protein. Fine mapping of this binding site revealed that this was a part of an antigenic domain. In Western blots, the monoclonal antibodies reacting with this domain also reacted with a second protein which was possibly the V-protein.

Amino Acid Sequence↗
PubMed1995

Experimentally induced "late-onset" mucosal disease--characterization of the cytopathogenic viruses isolated.

Antigenic and genetic analyses were performed in order to establish relationships between the noncytopathogenic (ncp) and the cytopathogenic (cp) bovine viral diarrhoea viruses (BVDV) involved in the induction of a case of experimentally induced "late-onset" mucosal disease (MD) symptoms. The persistent ncpBVDV, the cpBVDV used for superinfection (strain TGAC) and the virus isolates from faeces (cpX) were examined using an immunoplaque test (IPT) to distinguish between cp and ncp virus populations. The cp populations were cloned by plaque purification and found to be free of ncpBVDV when using the IPT. The cpBVDV clones and the persistent ncpBVDV were analysed in an enzyme immunoassay on heat-fixed infected cells (IM-EIA) and in a neutralization test using a panel of 27 monoclonal antibodies against the E0 (gp48) and E2 (gp53) viral glycoproteins. It was found that strain TGAC contained two antigenically distinct subpopulations of cpBVDV (TGAC-B1 and TGAC-B2). The endogenous ncpBVDV and the cpX clones had the same reactivity pattern in both tests. In addition, p80 gene duplications in the genomes of the cpBVDV clones were analysed using the polymerase chain reaction and subsequent restriction enzyme analysis of the amplicons. The clones analysed from TGAC-B1 and those from cpX had gene duplications of identical sizes showing the same restriction enzyme patterns. Our results suggest that the cpBVDV which finally lead to "late-onset" MD arose by recombination and/or by mutations of the cpBVDV used for superinfection.

Animals↗
PubMed1994

Demonstration of Sindbis virus antigen in Lowicryl-embedded cultured cells by immunogold staining.

Eight monoclonal antibodies (MAbs) were tested for the use in immunogold staining of Sindbis virus (SIN) antigen in cultured Baby Hamster kidney (BHK) cells. The antibodies were directed against the capsid (C) protein (5) or against the glycoprotein E1 (3), respectively. Four out of five anti-C MAbs and two out of three anti-E1 Mabs reacted on frozen sections, whereas two of the anti-C antibodies and none of the anti-E1 antibodies reacted on Lowicryl K4M-embedded cells. The MAbs reacting, in particular the anti-C Mabs which react on Lowicryl K4M-sections, will allow further studies of the pathogenesis and replication of alphaviruses on the cellular level. The results also confirm the conformation-dependence of the glycoprotein epitopes.

Acrylic Resins↗
PubMed1994

[Methods for the detection of viral contamination in food of animal origin].

Contamination of foods of animal origin with pathogenic human viruses may occur during handling or through polluted water. Most of these viruses are pathogens originating from the human gastrointestinal tract. They can be transmitted by the consumption of contaminated food and often cause disease. A survey is given of DNA- and RNA-viruses that may occur as contaminants of foods. In addition, the classical methods for detecting viral contaminations in foods are summarized. They are based on the effects after virus inoculation of cell cultures. Besides the fact that these methods are not economic and time consuming, they do not permit detection of some of the most important foodborne gastroenteritis viruses. The possibility of replacing these methods by detecting the viral genomes using hybridization and polymerase chain reaction (PCR) is discussed.

Animals↗
PubMed1993

RNA insertions and gene duplications in the nonstructural protein p125 region of pestivirus strains and isolates in vitro and in vivo.

Sixteen cytopathogenic (cp) bovine viral diarrhea virus (BVDV) strains/isolates were screened for the existence of RNA insertions in the p125 gene region and/or for p80 gene duplications using the polymerase chain reaction after reverse transcription. Three strains/isolates were shown to contain insertions, and in three others gene duplications were demonstrated. One strain was shown to contain a gene duplication in addition to an insertion. Insertions or duplications were absent in the genomes of 10 non-cp BVD virus strains/isolates, in 4 hog cholera (HC) virus strains, and in 9 of the 16 cp BVD virus strains/isolates analyzed. These results indicate that RNA insertions and gene duplications, although significant, are not the only mechanism contributing to cytopathogenicity in vitro. The RT-PCR was also applied to RNA isolated from tissues of a calf suffering from mucosal disease. Insertion-containing amplification products could be demonstrated in an organ-specific pattern.

Animals↗
PubMed1993

Distribution of cytopathogenic and noncytopathogenic bovine virus diarrhea virus in tissues from a calf with experimentally induced mucosal disease using antigenic and genetic markers.

A comparative analysis of the distribution of cytopathogenic (cp) and noncytopathogenic (ncp) bovine virus diarrhea disease (BVD) virus in tissues from a calf with experimentally induced mucosal disease was performed using immunohistology and polymerase chain reaction after reverse transcription (RT-PCR) of viral RNA. For immunohistology, an antigenic marker on the superinfecting cp BVD virus defined by a monoclonal antibody (mab) was used, and overall presence of antigen was assessed with a pestivirus specific mab. The primers selected for RT-PCR detected the genomic insertion in the p125 region of the superinfecting cp BVD virus. Both methods gave consistent results.

Animals↗