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Biomedical subjects

W Eichhorn

Publications and source records attributed to W Eichhorn.

At least 19 recordsLinked to original sources

Studies of epidemiology and seroprevalence of bovine noroviruses in Germany.

Jena virus (JV) is a bovine enteric calicivirus that causes diarrhea in calves. The virus is approximately 30 nm in diameter and has a surface morphology similar to the human Norwalk virus. The genome sequence of JV was recently described, and the virus has been assigned to the genus Norovirus of the family CALICIVIRIDAE: In the present study, the JV capsid gene encoded by open reading frame 2 was cloned into the baculovirus transfer vector pFastBac 1, and this was used to transform Escherichia coli to generate a recombinant bacmid. Transfection of insect cells with the recombinant baculovirus DNA resulted in expression of the JV capsid protein. The recombinant JV capsid protein undergoes self-assembly into virus-like particles (VLPs) similar to JV virions in size and appearance. JV VLPs were released into the cell culture supernatant, concentrated, and then purified by CsCl equilibrium gradient centrifugation. Purified JV VLPs were used to hyperimmunize laboratory animals. An antigen capture enzyme-linked immunosorbent assay (ELISA) was developed and characterized initially with clinical specimens containing defined human noroviruses and bovine diarrheal samples from calves experimentally infected with JV; the ELISA was specific only for JV. The ELISA was used to screen 381 diarrheal samples collected from dairy herds in Thuringia, Hesse, and Bavaria, Germany, from 1999 to 2002; 34 of these samples (8.9%) were positive for JV infection. The unexpectedly high prevalence of JV was confirmed in a seroepidemiological study using 824 serum or plasma samples screened using an anti-JV ELISA, which showed that 99.1% of cattle from Thuringia have antibodies to JV.

Animals↗

Recent developments in the epidemiology of virus diseases.

There is continual variation in viral epidemics regarding clinical symptoms, duration and disappearance, and the emergence of new diseases. This can be observed in both human and animal diseases. This evolution of virus diseases is mainly related to three factors: aetiological agent, host and environment. As far as genetic alterations of the virus are concerned, two major mechanisms are involved: mutations such as recombination and reassortment; and selection for resistance or susceptibility. This review focuses on the epidemiology of newly emerged virus diseases in man and animals, such as acquired immunodeficiency syndrome, haemorraghic fevers, bovine spongiform encephalopathy, canine haemorraghic disease and respiratory syndrome in horses.

Animals↗

Equine herpesvirus type 1 (EHV-1) myeloencephalopathy: a case report.

An outbreak of neurological disease occurred in a well-managed riding school. Ataxia and paresis were observed in several horses, five of which became recumbent and were euthanized. Post-mortem analysis revealed scattered haemorrhages along the spinal cord, that were reflected by multiple haemorrhagic foci on formalin-fixed sections, with the thoracic and lumbar segments being the most affected. Pathohistologically, perivascular mononuclear cuffing and axonal swelling, especially in the white matter, were evident. Parallel to the course of disease, alterations in myelin sheets and activation of astrocytes and microglial cells were also observed. Virological findings confirmed an acute equine herpesvirus type 1 infection and virus was isolated from the spinal cord of a 26-year-old mare.

Animals↗

[Bile acid concentrations in serum, bile and feces of healthy calves and calves with diarrhea].

On 32 calves (age 3 to 14 days) with spontaneously occurring diarrhoea, the following investigations were carried out: Regular examination of serum bile acid concentrations, collection of the entire faeces with determination of bile acid concentrations, as well as microbiological examinations. Six clinically healthy calves served as control group. In addition, bile acids in bile were determined in 16 other calves of the same age group and in 6 beef bulls. There was no significant influence of daytime or feed intake on serum bile acid concentration in diarrhoeic or healthy calves. Possibly due to the low concentrations of bile acids in the bile of young calves (4.8 +/- 3.7 mmol/l, compared to 57 +/- 13 mmol/l in the bulls), the concentrations in faeces were also rather low (control group 623 +/- 92, calves with diarrhoea 318 +/- 277, after diarrhoea. 794 +/- 935 mumol/kg). Most of it was cholic acid, whereas only traces of desoxycholic acid were found. In spite of the comparatively low concentrations of fecal bile acids, the diarrhoeic calves excreted larger amounts of bile acids than the healthy calves (12.7 +/- 13.5 vs. 1.4 +/- 0.8 mumol/kg), but this was independent of the type of enteropathogen or pathogen combinations which were detected. There were no indications for a direct influence of the diarrhoea by bile acids. However, through enteral bile acid losses, profuse diarrhoea lasting several days can cause a reduction in the total bile acid pool.

Animals↗

[Effect of steam application based on microbiological and parasitologic test procedures].

In the present study steam application was investigated with regard to microbicidal and parasiticidal effects. The cleaning apparatus used (Uninova Company) works at a boiler pressure of about 5 bar and consequently with a temperature up to 155 degrees C inside the boiler. Whereas the ambient atmosphere working temperature of steam is slightly below 100 degrees C. The tests are based on the DVG guidelines for testing chemical disinfectants (2). Different steaming times and distances were used in germ carrier tests with three different germ carriers (tile, wood, carpet) and three different test germs (Staphyloccocus aureus, Pseudomonas aeruginosa, Candida albicans) in order to determine the optimum conditions for biocidal effects of steam-application. These optimum conditions were additionally tested with two test viruses (ECBO- and Reo-virus) and a parasitological resting form (ascarid worm eggs). Swirling of germs caused by steam turbulence was minimized by covering the steam outlet nozzle with cloth. The experiments showed logarithmical reduction factors of at least 5.0 in the germ count at steaming times of 5 seconds and a steaming distance of 2.5 cm for all three test germs on all three germ carriers (mean of 10 repeated tests). The virological tests showed good disinfection results after a steaming time of only 2 seconds using aseptic gauze as germ carrier and also after 5 seconds using wood as a carrier. Finally in testing vitality of undeveloped Ascarid worm eggs only 2 seconds of steam treatment proved to be sufficient for a 100 percent destruction. According to the present results steam treatment is most likely to become a valuable, ecologically compatible method in controlling hygienic problems, with a potential of partly replacing chemical disinfectants. In particular we see applications in keeping pets and companion animals, provided the above mentioned rules are followed (steaming distance 2.5 cm; steaming time 5 seconds; cloth). In farm animal stables steam disinfection seems harder to achieve because of large, rough surfaces and economical reasons as e.g. expenditure of time and energy.

Animals↗

Equine viral arteritis with abortions: serological and virological evidence in Germany.

An outbreak of clinical disease with abortions, suspected to be equine viral arteritis in Germany was examined serologically and virologically. Three of five animals tested seroconverted to EAV, and EAV was isolated from an aborted fetus. In view of the significant increase in seropositive horses, the need for control measures is emphasized.

Abortion, Veterinary↗

[Diagnostic imaging of microcirculation of pedicled flap-plasties of the mandibulofacial area using the laser Doppler scanner].

Objective, non-invasive examination techniques in addition to clinical parameters are required to monitor the wound healing of flaps. With the new Laser-Doppler Scanner (LDI, PIM 1.0 Lisca Development AB, Sweden) it is possible to measure and visualize microcirculation continuously, non-invasively and without contact to the wound in an area of 12 x 12 cm. We performed measurements and simultaneous two-dimensional imaging of microcirculation 24, 48, 72 hours and five and 14 days postoperatively in 22 patients, who received reconstruction procedures with random or axial pattern flaps. The perfusion diagrams were correlated to the clinical aspect. Necrotic areas, venous stasis, and normal course of wound healing can be clearly visualized and differentiated. The new Laser-Doppler Imaging System (LDI) serves as an excellent aid for control and planning of flaps in plastic and reconstructive surgery.

Adolescent↗

Vasoconstrictors during pregnancy--in vitro trial on pregnant and nonpregnant mouse uterus.

In an in vitro trial on 80 pregnant and nonpregnant mice, the sensitivity of the uterus myometrium to the vasoconstrictors vasopressin, ornipressin, epinephrine, and norepinephrine was examined in comparison with oxytocin as a standardized stimulative drug. The pregnant uterus showed a significantly increased sensitivity to ornipressin, vasopressin, and norepinephrine. Epinephrine showed no uterus-stimulating effect, and an increase of sensitivity caused by pregnancy was not detected.

Animals↗

Laser Doppler imaging of axial and random pattern flaps in the maxillo-facial area. A preliminary report.

Objective, non-invasive examination, techniques in addition to clinical parameters, are required to follow-up the wound healing of flaps. With the new laser Doppler Scanner (LDI DIM 1.0 Lisca Development AB, Sweden) it is possible, for the first time, to measure and image the microcirculation continuously, non-invasively and without contact with the wound, in an area of 12 cm square maximum. We performed measurements and simultaneous two-dimensional imaging of the microcirculation 24, 48, 72 h and 5 and 14 days postoperatively in 20 patients, who had had reconstruction procedures performed using random or axial pattern flaps. The perfusion diagrams were correlated to the clinical appearance. Necrotic areas, venous stasis and normal course of wound healing can be clearly visualized and differentiated from one another. The new laser Doppler imaging system seems to be an excellent aid for following up and planning of flaps in plastic and reconstructive surgery.

Adolescent↗

Bovine rotavirus V1005 a P5, not a P12, type like all viruses in a German survey.

Bovine rotavirus (BRV) V1005, like 34 further cell culture-adapted strains in a 6-year survey in Upper Bavaria, Germany, is not a P12 but a P5 P-type rotavirus. The conclusion is based on dot blot hybridization with P1-, P5-, and P11-specific cDNAs, encompassing the VP8* region of major sequence diversity, and on PCR using P1-, P5-, and P11-specific primer pairs derived from the VP5* region of VP4 (VP5* and VP8*, respectively, are the larger and smaller tryptic cleavage products of VP4). Sequencing of the hyperdivergent region of VP4 confirmed the close relatedness of BRV V1005 to BRV UK, the P5 prototype virus.

Amino Acid Sequence↗

Rapid identification and differentiation of the vaccine strain Rac H from EHV 1 field isolates using a non-radioactive DNA probe.

A method for rapid differentiation between the EHV 1 live vaccine strain Rac H and field isolates is described. Total DNA was isolated from virus-infected small scale cell cultures. DNA fragments digested with restriction endonuclease BamHI were separated, transferred and immobilized on filter membranes. A Digoxigenin-labeled probe derived from EHV 1 was used for hybridization. This probe hybridized specifically to sequences of the inverted terminal repeat region which in case of Rac H include a deletion of 0.8 kb. By comparing the different migration patterns after blot hybridization it could be shown that in 65 isolates from cases of abortion the live vaccine strain Rac H was not involved.

Abortion, Veterinary↗

Rotavirus 993/83, isolated from calf faeces, closely resembles an avian rotavirus.

Polypeptides from purified virions of the calf rotavirus (RV) isolate 993/83 and those from the pigeon RV isolate PO-13 comigrated on SDS-polyacrylamide gels. Two polypeptides of 45K and 47K were detected at the position of VP6. Both proteins behaved like authentic VP6 protein with EDTA and heat treatment. RV 993/83 and PO-13 showed identical one-dimensional peptide maps for VP2, and the 45K and 47K proteins. More than 70% of sera from German cattle older than 1 year showed neutralizing serum antibodies to RV 993/83 and RV PO-13.

Animals↗

Isolation of an avianlike group A rotavirus from a calf with diarrhea.

An atypical group A rotavirus (993/83) was isolated from a 3-day-old German calf with diarrhea. It differed from 35 conventional German bovine rotavirus isolates analyzed previously with respect to subgroup (strain 993/83 was non-subgroup I and non-subgroup II), serotype (strain 993/83 showed a two-way cross-reaction with serotype 7 and a one-way cross-reaction with serotype 3), and electropherotype (strain 993/83 showed comigrating gene segments 10 and 11). Isolate 993/83 reacted with only one of four monoclonal antibodies that recognized a common VP6 epitope(s). In addition, VP6 and VP2 of isolate 993/83 showed one-dimensional peptide maps that differed substantially from the peptide maps of VP6 and VP2 from all bovine rotavirus isolates. By RNA-RNA hybridization, the 993/83 probe failed to react with a panel of mammalian rotavirus strains, including bovine rotaviruses. It hybridized, however, to genomic RNA of an avian rotavirus strain. Isolate 993/83 could thus represent a candidate for a natural interspecies transmission of rotavirus between different classes of vertebrates.

Animals↗

Cattle develop neutralizing antibodies to rotavirus serotypes which could not be isolated from faeces of symptomatic calves.

Neutralizing antibodies against 10 serotypes of rotavirus were measured in sera from different age groups of German cattle. Only five of 143 sera did not neutralize heterologous serotypes. Sera from 64 of 76 calves younger than 1 year neutralized bovine rotavirus NCDV (serotype 6). From these calves, sera 54, 26, 51, 24, 12, 10 and 37, in neutralized addition, the heterologous serotypes 1, 2, 3, 4, 5, 7 and 9, respectively. Thirty-eight of 46 rotavirus isolates from Bavarian calves with diarrhoea were serotyped by neutralization: 22, 2 and 14 isolates were typed as serotype 6, serotype 10 (B223) and a newly defined subtype of serotype 10 (V1005), respectively. All serotype 6 isolates and none of the serotype 10 or V1005-like viruses tested hybridized to a NCDV-specific cDNA probe. Eight isolates gave equivocal results by neutralization. We failed however to identify serotype 1, 2, 3, 4 or 8 bovine rotavirus isolates by neutralization with hyperimmune sera and dot blot hybridization with serotype-specific cDNA probes. Thus cross-reacting antibodies in cattle might not represent an anamnestic response, but the recognition of a cross-reacting neutralization epitope shared by many rotavirus serotypes.

Animals↗

Coronavirus as an agent of neonatal calf diarrhea in a Chinese dairy cattle farm.

Neonatal calf diarrhea is a significant health problem in dairy industry in the whole world. Although the aetiological agents of neonatal diarrhea are diverse, it is obvious that viruses play an important role. One of them is bovine coronavirus (BCV). Since BCV was discovered (MEBUS et al., 1969), there have been many published reports describing the virus and its importance in calves. In China, we first investigated the seroepidemiological status of BCV infections in cattle (YAO et al., 1990). The results showed that the incidence of infections with BCV in cattle in different chinese regions are high. Further work on direct diagnosis of BCV as a causative agent of diarrhea was therefore necessary. In the last years we have developed diagnostic methods including a monoclonal antibody-based ELISA to detect BCV and other diarrheal viruses. In this study, the diagnosis of an outbreak of BCV in chinese dairy cattle is described.

Animals↗

Prevalence of antibodies to four bovine rotavirus strains in different age groups of cattle.

Neutralizing antibody titers to four bovine rotavirus strains, representing three serotypes, were measured in 160 sera from cattle of different age groups. Age-specific seroprevalence analysis revealed serotype 6, represented by bovine rotavirus (BRV) NCDV, as the predominant rotavirus serotype infecting German cattle and serotype 10, represented by BRV V1005, as the least prominent. Infections with serotype 8, represented by BRV 678, occurred with intermediate frequency. Antibodies of young calves distinguished between NCDV and UK virus, two serotype 6 BRV strains differing in VP4 antigen.

Age Factors↗

Antigenic and biochemical characterization of bovine rotavirus V1005, a new member of rotavirus serotype 10.

Bovine rotavirus (BRV) V1005 is serologically distinct from rotavirus serotypes 1, 2, 3, 4, 5, 6, 8 and 9. BRV V1005 showed cross-reactions with BRV B223, the American prototype of serotype 10 rotavirus, and with BRV E4049, a British serotype 10 isolate. BRV V1005 was, however, not neutralized by four monoclonal antibodies directed against VP7 of BRV B223. Two-way cross-reactions were observed between BRV V1005 and a reassortant rotavirus containing the VP4 from BRV UK. In addition the major tryptic cleavage product of VP4, VP5*, from BRV V1005 is indistinguishable by peptide mapping and its isoelectric point from the homologous protein of BRV UK, but is clearly different from VP5* of BRV NCDV. The peptide map of VP7 from BRV V1005 differed from that obtained for VP7 of BRV UK.

Animals↗

Characterization of monoclonal and polyclonal antibodies to bovine enteric coronavirus: establishment of an efficient ELISA for antigen detection in feces.

Monoclonal antibodies to bovine enteric coronavirus (BEC) were produced. Additionally, polyclonal antibodies were made in rabbits and guinea pigs and extracted from the yolk of immunized hens. The antibodies were characterized by neutralization test, hemagglutination inhibition test, enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Neutralizing antibody titers of polyclonal antisera ranged from 1:1280 to 1:40,000. Only one out of 908 hybridoma colonies tested secreted antibodies with neutralizing activity. By ELISA, polyclonal sera exhibited high background reactions that could be significantly reduced by treatment with kaolin in the case of rabbit sera. Attempts to establish an ELISA for BEC antigen detection based on polyclonal sera failed due to low sensitivity and specificity. Optimal results were achieved when a mixture of two monoclonal antibodies was coated onto microplates for antigen capture, while rabbit hyperimmune serum served as detecting antibodies in an indirect assay. The combination of the two monoclonal antibodies did not increase sensitivity synergistically, but in a compensatory fashion, probably because of epitope differences between BEC field strains.

Animals↗