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Biomedical subjects

V Moennig

Publications and source records attributed to V Moennig.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Persistent BVD virus infections in a cattle breeding facility--a case report].

Comprehensive serological and virological monitoring for bovine viral diarrhoea (BVD) virus was applied in a dairy herd. Out of 83 calves 26 persistently infected animals were identified. Four viremic calves showed clinical signs of disease, the others displayed no symptoms. Viral isolates from persistently infected animals were homogenous with respect to their antigenicity. The results of virological and serological investigations allowed an almost complete reconstruction of events following the introduction of BVD virus into the herd. This case illustrates the potentially dangerous and damaging effects of unidentified virus carriers in cattle herds. Strategies for the identification of virus-shedding animals and the limitation of economical losses are discussed.

Animals↗
PubMed1992

[Changes in the dynamics of viral infectious diseases].

Modern methods of molecular biology are suitable to analyse evolutionary processes in the area of infectious diseases. Visible expression of this evolution is the emergence of "new" infectious agents, e.g., canine parvovirus, the agent of the porcine reproductive and respiratory syndrome and phocine distemper virus. In addition a gradual change of disease syndromes may be observed, e.g., classical and African swine fever and myxoma. These processes are based on genomic changes of the respective infectious agents, i.e., point mutations and recombinations. Especially RNA viruses are prone to genomic change, and the plasticity of their genomes enables them to adapt to varying selective pressures. Human activities in agriculture, global commerce and tourism may enhance and precipitate microbial evolution.

Animals↗
PubMed1991

Distribution of antigen of noncytopathogenic and cytopathogenic bovine virus diarrhea virus biotypes in the intestinal tract of calves following experimental production of mucosal disease.

Mucosal disease can be experimentally induced by inoculating calves persistently viremic with noncytopathogenic (ncp) Bovine Virus Diarrhea Virus (BVDV) with an antigenetically closely related cytopathogenic (cp) BVDV strain. Calves suffering from mucosal disease develop severe intestinal lesions causing breakdown of the gastrointestinal barrier and death. Knowledge about tissue distribution of ncp/cp biotypes of BVDV may contribute to the understanding of the pathogenesis of these lesions. Distribution of cpBVDV versus ncpBVDV was demonstrated in the intestinal tract of nine calves with experimentally induced mucosal disease and in five persistently viremic calves. Biotypes were distinguished immunohistochemically in organ tissues using monoclonal antibodies against marker epitopes on the viral surface glycoprotein gp53. In persistently viremic calves ncpBVDV was present in a few epithelial cells, mononuclear cells and intramural ganglia. A multifocal reaction was observed in vascular walls. In calves with mucosal disease a striking increase of antigen containing cells occurred. Viral antigen in these cells reacted with marker antibodies for cpBVDV. A distinct tissue distribution of biotypes was observed in intramural ganglia and duodenal glands. Severe tissue damage was correlated to the presence of cpBVDV antigen. This indicates the importance of cpBVDV for the development of lesions. Interactions of cpBVDV and immunemediated mechanisms will need further investigation.

Animals↗
PubMed1991

Correlation of bovine viral diarrhoea virus induced cytopathic effects with expression of a biotype-specific marker.

The purpose of this study was the identification antigenic differences between cytopathic (cp) and noncytopathic (ncp) bovine viral diarrhoea viruses (BVDV). Cells infected with 19 strains of each viral biotype were analyzed for reactivity with the monoclonal antibody (mab) BVD/C38. Reactivity was examined using an enzyme immunoassay on fixed infected monolayers of fetal calf kidney cells. In the majority of cases, the mab discriminated between cells infected with each of the two viral biotypes. Three reactivity patterns could be distinguished. Most cpBVDV strains yielded monolayers where 80-100% of infected cells reacted with the mab. Most of the ncpBVDV infected cells showed either no reaction, or only single cells of foci were stained. However, about one third of either cp- or ncpBVDV strains tested yielded infected monolayers where 30-50% of the cells reacted with the antibody. Cell damage other than the typical cytopathic effect might be responsible for the BVD/C38 reactivity of cells infected with BVDV. In addition, it was analyzed whether the antigenic marker associated with cpBVDV was expressed in cells infected with viral isolates from 21 animals with clinical mucosal disease. In 14 cases cpBVDV was isolated and the antigenic marker was found throughout. In seven cases ncpBVDV was cultivated and the antigenic marker was detected in four isolates.

Animals↗
PubMed1991

The development of an international reference panel of monoclonal antibodies for the differentiation of hog cholera virus from other pestiviruses.

A panel of 30 monoclonal antibodies was defined and characterized with respect to the binding capacity in immunoperoxidase assay to different strains of pestivirus. Using the panel it was possible to identify specifically all strains and isolates of hog cholera virus, hog cholera vaccines derived from 'C' strains, and most strains of bovine viral diarrhoea/border disease (BVD/BD) viruses (including those isolated from pigs). A small proportion of BVD/BD isolates from pigs and ruminants reacted only with the monoclonals specific for pestivirus group antigen. It is recommended that monoclonal typing methods be introduced into official procedures for the diagnosis of hog cholera/classical swine fever.

Animals↗
PubMed1991

Immunofluorescence studies of biotype-specific expression of bovine viral diarrhoea virus epitopes in infected cells.

The expression of biotype-specific epitopes in cells infected with cytopathic (cp) and non-cytopathic (ncp) bovine viral diarrhoea virus (BVDV) was analysed by immunofluorescence. Four monoclonal antibodies (MAbs) directed against different epitopes on the viral glycoprotein gp48 were used. With cells infected with cpBVDV strain NADL, the four MAbs yielded a strong and granular cytoplasmic fluorescence. The same pattern was observed when cells were infected with ncpBVDV 7443 with two of the MAbs (BVD/C12, BVD/C42). In contrast, reactivity with the other two MAbs (BVD/C38, BVD/C46) was restricted to a narrow perinuclear zone. These biotype-specific differences were not observed either with a gp53-specific MAb, or with an MAb specific for the non-structural protein p125/p80. Double immunofluorescence staining of living cells with a polyclonal BVDV-specific serum and with the MAbs revealed that expression of viral proteins on the surface of cells infected with cp- or ncpBVDV, respectively, was not detectable.

Animals↗
PubMed1991

Clinical, post mortem and virological findings after simultaneous inoculation of pigs with hog cholera and bovine viral diarrhoea virus.

The clinical course, post mortem lesions as well as virological and serological results after simultaneous intranasal inoculation of pigs with bovine viral diarrhoea virus (BVDV) and hog cholera virus (HCV) are described. Five groups of four weaners received constant doses of BVDV strain OSLOSS/2482 and tenfold decreasing doses of HCV strain ALFORT/187. Doses of 1,000 and 100 TCID50 of HCV in groups A and B of pigs led to fever and severe clinical signs in all animals of two groups, whereas at higher dilution of inoculum two, three or four animals survived without any clinical signs in the respective groups (C-E). Leucocyte samples taken from febrile animals and from normal pigs on five consecutive days were inoculated into both fetal calf kidney (FCK) and PK (15) cell cultures. Virus isolates were differentiated with BVDV and HCV specific monoclonal antibodies. HCV viraemia was detected in febrile animals exclusively, and BVDV viraemia occurred in not affected animals on days 3 to 7 post inoculation. Neutralizing antibodies (nab) against BVDV appeared before HCV nab in surviving animals of groups C and D after receiving low doses of HCV (10 or 1 TCID50). No BVDV nab were detected in group E that had received such a high dilution of HCV in addition to BVDV that theoretically no HCV was applied.

Animals↗
PubMed1991

Detection of alphaviruses in a genus-specific antigen capture enzyme immunoassay using monoclonal antibodies.

A genus-specific antigen capture assay using similar combinations of monoclonal antibodies for capture and detection of 24 alphaviruses belonging to the seven serocomplexes was developed. The sensitivity of the test ranged from 10(3.4) 50% tissue culture infective doses/ml for o'nyong-nyong virus to 10(6.1) 50% tissue culture infective doses/ml for Middelburg virus. The antigen capture test uses a combination of cross-reacting monoclonal antibodies directed against the nucleocapsid protein and envelope glycoprotein E1 of Semliki Forest virus.

Aedes↗
PubMed1991

[A new enzyme immunoassay for the detection of antibodies against the bovine viral diarrhea virus].

An enzyme-linked immunosorbent assay (ELISA), using the nonstructural protein p125/80 of the bovine viral diarrhoea (BVD) virus as antigen, was used for screening BVD-specific antibodies in 468 bovine sera. The results were compared with those obtained in a standard neutralization test (NT). Both tests reacted positive with 457 sera. The ELISA gave positive results with eight sera which were negative in the NT whereas one serum was positive in the NT and negative in the ELISA. Two sera could not be tested in the NT because they were toxic for the cultured cells. In addition the sera were screened in an ELISA using the equivalent heterologous nonstructural protein of hog cholera virus as antigen. The results obtained in both ELISAs showed a correlation of 94%.

Animals↗
PubMed1991

[A sensitive enzyme-linked immunosorbent assay (ELISA) for the serological detection of antibodies against the European hog cholera virus].

An ELISA for the detection of antibodies against hog cholera virus (HCV) was developed. The HCV-specific glycoprotein gp53 served as diagnostic antigen after immobilization using a monoclonal capture antibody. Due to the higher affinity of HCV-specific antibodies to the viral gp53, sera cross reacting with bovine viral diarrhea (BVD) virus were discriminated by the slope of the titration curves.

Animals↗
PubMed1991

[Use of monoclonal antibodies for the differential diagnosis of pestivirus infections in swine].

Monoclonal antibodies (mab) specific for hog cholera virus (HCV), bovine viral diarrhoea virus (BVDV) or pestivirus were applied for the differential diagnosis of pestivirus infections in pigs. Field virus isolated from 8 confirmed classical swine fever outbreaks and one suspect case was propagated in PK(15) cell cultures and identified by direct immunofluorescence (IFA) and peroxidase linked antibody (PLA) assays. Peroxidase-linked HCV, BVDV and pestivirus specific mab were applied in direct PLA for differentiation. Nine isolates were classified as members of the genus pestivirus. Eight isolates showed a positive reaction with an HCV mab. One isolates reacted with BVDV specific mab only. For further characterization an indirect PLA was performed using a collection of different HCV and BVDV specific mabs. Some of the HCV isolates also showed a weak reaction with BVDV specific mab.

Animals↗
PubMed1991

[Analysis of sera from two cattle herds suspected of brucellosis using a competition enzyme immunoassay with monoclonal antibodies].

The milk pools of two cattle herds in Lower Saxony were found to give positive results in an enzyme-linked immunosorbent assay (ELISA). The sera from these cattle were tested in competition enzyme immunoassays (cEIA) using two monoclonal antibodies. The results were compared to those obtained in the serum agglutination assay (SLA) and in an ELISA. The cEIAs detected more positive samples than the other tests. All sera that were positive in the SLA and in the ELISA were also positive in the cEIAs. Due to the higher sensitivity, these tests may be an alternative for the SLA.

Agglutination Tests↗
PubMed1990

Reproduction of mucosal disease with cytopathogenic bovine viral diarrhoea virus selected in vitro.

Isolates of non-cytopathogenic bovine viral diarrhoea (BVD) virus from 18 persistently infected calves from one herd were compared by using monoclonal antibodies directed against the major viral glycoprotein gp53. All the isolates displayed an almost identical reaction pattern. Based on this antigenic analysis three cytopathogenic BVD and three non-cytopathogenic BVD viruses closely related to the non-cytopathogenic BVD herd isolate were selected. Six of the persistently infected calves were inoculated with a pool of the three closely related cytopathogenic BVD viruses and two with a pool of the three non-cytopathogenic BVD viruses. In addition three animals were infected with one closely related cytopathogenic BVD strain (Indiana) and two animals with the antigenetically different cytopathogenic BVD viral strain A1138/69. Regardless of the inoculation route all the animals superinfected with closely related cytopathogenic BVD viruses developed the characteristic lesions of mucosal disease within 14 days of infection. Animals which were inoculated with non-cytopathogenic BVD viruses which closely resembled the herd isolate, or with cytopathogenic BVD viruses which did not resemble the herd isolate did not develop any signs of disease. However, the latter group produced antibodies to the superinfecting virus.

Animals↗
PubMed1990

Identification of conserved epitopes on a hog cholera virus protein.

Eight monoclonal antibodies directed against the hog cholera virus (HCV) strain Alfort/187 and displaying broad cross-reactivity with other HCV strains were characterized. An enzyme immunoassay on fixed monolayers of porcine or bovine cells infected with 14 different strains and isolates of HCV and 12 bovine viral diarrhea viruses (BVDV), respectively, showed that all antibodies reacted with HCV only. Seven antibodies recognized all HCV tested, thus indicating that they were directed against conserved epitopes. All antibodies neutralized the homologous strain and different patterns of the other HCV tested. Radioimmunoprecipitation analysis showed that the monoclonal antibodies were directed against a doublet of 56-60 kDa, presumably representing the major envelope glycoprotein of HCV. The results of reciprocal antibody blocking assays allowed the mapping of two distinct conserved antigenic domains on this protein.

Animals↗
PubMed1990

Immunohistological detection of bovine viral diarrhoea virus antigen in the central nervous system of persistently infected cattle using monoclonal antibodies.

In a total of 25 cattle persistently infected with bovine viral diarrhoea virus (BVDV) the distribution of viral antigens in the central nervous system was studied. Using a panel of monoclonal antibodies (anti pestivirus C16; anti cytophathic BVDV C38; anti cytopathic and non-cytopathic BVDV C42; anti gp53 BVDV CA-1 and CA-3) and the indirect immunoperoxidase technique, BVDV antigen was located exclusively in neurons. Predilection sites for viral persistence were cerebral cortex and hippocampus. Morphological cellular alterations were not seen. Reactive perivascular lymphocytic infiltrations were occasional findings.

Animals↗
PubMed1990

Use of biotechnical methods in veterinary medicine.

Biotechnological methods offer promising approaches for improved diagnostic and prophylactic purposes. The following biotechnological techniques are used in the Institute of Virology at the Hanover Veterinary School:--Production of monoclonal antibodies directed against viral and bacteria-specific antigens such as bovine virus diarrhoea virus, classical swine fever (hog cholera) virus, feline leukaemia virus, animal parvoviruses, Alphavirus, Brucella and Francisella--Establishment of improved and sensitive diagnostic enzyme immunoassays (ELISA) using monoclonal antibodies--Molecular cloning and sequencing of classical swine fever virus RNA and parvovirus DNA--Development of diagnostic hybridisation techniques (dot, slot, Southern and Northern blot, in situ, oligonucleotides)--Detection of viral genomes in tissues of infected animals--Development of synthetic oligopeptides as diagnostic antigens and as potential immunogens for vaccines. Currently available techniques used in basic research (e.g. pathogenesis studies) will be tested for their application in routine diagnosis of viral diseases, e.g. by molecular hybridisation. Some techniques need to be simplified (e.g. RNA extraction procedures) and, particularly, alternative labelling schedules must be developed (e.g. biotin or sulfone labelling instead of radionuclides).

Aleutian Mink Disease Virus↗
PubMed1990

Ruminant pestivirus infection in pigs.

Ruminant pestivirus infections of pigs have a worldwide distribution. The prevalence is varied and depends mainly on (i) contact with cattle, (ii) age of pigs and (iii) degree of homology of virus strains used for serology, with field strains of bovine virus diarrhoea virus (BVDV) infecting pigs. Emphasis should be laid on sources of BVDV other than cattle, e.g. contaminated vaccines and fetal calf serum. The need for differentiation of pestiviruses (hog cholera, bovine virus diarrhoea and Border disease viruses) is highlighted by the fact that clinical disease syndromes, e.g. growth retardation and wasting, are reminiscent of hog cholera. Monoclonal antibodies are available which differentiate between hog cholera virus (HCV) and ruminant pestiviruses, presumably BVDV. An up-to-date account of the antigenic relationship between pestiviruses is included in the review. Analysis of the in vitro host range of these viruses is considered to be important and may explain infections of pigs with pestiviruses other than HCV. Recent results have shown the existence of "specialists" amongst BVDV strains for bovine cells, and a few isolates also performed well in cultures of the PK15 cell line. In contrast, multipotent BVDV strains presumably have additional attachment sites for ovine and porcine cells. Identification of receptors on ovine and porcine cells could contribute to a clear distinction between BVDV and HCV infections of pigs. Immediate control measures for BVDV infections of pigs are not required. However, such infections may interfere with serologic surveys and surveillance on a herd basis and, therefore, impair eradication programmes and efforts to maintain the status in countries declared free of hog cholera.

Animals↗