Biomedical subjects

O C Straub

Publications and source records attributed to O C Straub.

At least 19 recordsLinked to original sources

PubMed1992

[Vaccination of sheep against Aujeszky's disease with a gI-deleted mutant].

The use of gl deleted live vaccines against Aujeszky's disease (AD) facilitates to differentiate vaccinated from field-virus infected animals. In this study different modes of vaccination were tried to find out how sheep can be protected from a lethal infection with ADV. It could clearly be demonstrated that Aujeszky disease virus (ADV) is spread by horizontal transmission from infected pigs to sheep. The nasal discharges of infected pigs contained a maximum of 10(8.75)TCID50/g mucus at days 3 and 4 p.i. and those of the contact-pigs 10(8.5)TCID50/g mucus at days 6 and 7 after contact. Non-vaccinated contact sheep were infected horizontally by the pigs. The highest titres ranged from 10(6.25) to 10(7.5)TCID50/g mucus. These animals were sacrificed at day 5 p.i. exhibiting acute symptoms of AD. The nasal discharge of vaccinated sheep contained much lower amounts of ADV (maximum: 10(4.25)TCID50/g mucus). All surviving animals had developed antibodies. Following challenge with the ADV-strain NIA3, no febrile response or virus-shedding was observed in sheep vaccinated 2x s.c. or 2x i.m. with a gl deleted live vaccine, whereas sheep, vaccinated only 1x i.m. (4 out of 4 animals) or 1x i.m. (3 out of 4 animals) or 1x i.n. and 1x i.m. (1 out of 4 animals) had to be sacrificed after showing acute symptoms of AD. In conclusion it can be stated that a double parental vaccination with a gl deleted live vaccine protects sheep against a field-virus AD infection.

Animals↗

PubMed1992

[Viral agents as the cause of reproductive disorders in cattle and available vaccines].

After a review on the viral agents playing a role in diseases of cattle those related to the occurrence in the genital tract are described. They may be causing abortion or local reactions leading to a reduced fertility and/or be of importance for the embryo transfer. Bovine herpesvirus type 1 (BHV1) and the bovine virus diarrhoea virus (BVDV) are the agents most widely distributed in Europe. Both are of economic importance, described in detail and vaccines available discussed.

Abortion, Veterinary↗

PubMed1991

BHV1 infections: relevance and spread in Europe.

Infections caused by BHV1 are very common in Europe, but the disease pattern is quite different: the diseases of the genital tract are most common, those of the respiratory tract vary in intensity and prevalence. Digestive disorders connected with BHV1 are in general only observed in calves and mainly in Belgium. Virus strains causing abortion or encephalitis are only present in a few countries. The same is true for BHV1 induced mastitis. Dermatitis and lesions in the interdigital space seem to be a rare event. BHV1 infections are frequently complicated by bacterial secondary infections, but there is evidence that BHV1 infections can occur simultaneously with bovine virus diarrhoea (BVD) and/or parainfluenza-3 (PI 3) virus. The biggest problem associated with BHV1 infection is the ability of the agent to become latent following a primary infection. The genome of the virus probably remains during the life of the animal in the ganglia of the region where the primary infection occurred. No vaccination can overcome this latent stage. By prophylactic vaccination it is possible to prevent an outbreak of clinical disease but it is impossible to prevent infection followed by the establishment of latency. Eradication programmes in Austria, Denmark and Switzerland have removed most of the seropositive cattle from the bovine populations. Currently a sanitary programme is also being conducted in Germany.

Animals↗

PubMed1991

Detection and localization of single-base sequence differences in foot-and-mouth disease virus genomes by the RNase mismatch cleavage method.

The RNase mismatch cleavage method was examined for its efficiency of indicating single-base sequence differences in the capsid protein-coding regions of different foot-and-mouth disease virus subtype O1 strains. The method was found suitable for indicating such differences. RNase A as well as RNase T1 contributed to substrate conversion. Examples for the cleavage of eleven different single-base mismatches in RNA double-strands are now known. All virus genomes found to differ from each other exhibited three or more non-neighboured single-base sequence differences. Other genomes found to be indistinguishable by this method were those of a recent field isolate adapted to cell culture, and those of a vaccine production strain; its progeny was transmitted to pig and cow and then analyzed. The results suggest that host change does not necessarily select for antigenic variant virus, and that virus submitted to some kind of selection pressure is changed at more than one position.

Animals↗

PubMed1990

[Development of an inactivated vaccine for the protection of cattle against Aujeszky's disease].

The effects of an inactivated strain of Aujeszky's disease vaccine in cattle were investigated. It has not been possible to use vaccines licensed for use in pigs successfully in cattle even though cattle develop neutralizing antibodies to these vaccines. The addition of zinc compounds to the vaccines resulted in protection in cattle. The basis for the use of zinc is discussed. A mutant based vaccine was effective following local administration, but was not when administered parenterally. Anti-prostaglandin was not effective either, despite its successful use in sheep when administered with BHV1. The vaccine presents a prospect for immunising dogs and cats, and the addition of zinc compounds to other drugs and inducers is discussed.

Animals↗

PubMed1990

Identification of foot-and-mouth disease virus replication in vaccinated cattle by antibodies to non-structural virus proteins.

Antibodies raised in cattle against foot-and-mouth disease virus by vaccination or by experimental infection were distinguished. Vaccination elicited only antibodies to virus capsid proteins and the polymerase 3D. Virus replication in cattle elicited additional antibodies directed against the non-structural proteins 2B, 2C, 3AB1, and/or 3C irrespective of prior vaccination or whether the cattle exhibited symptoms of disease. Non-permissive mice inoculated with virus responded in the same way, indicating that antibodies raised due to the transient presence of antigen are safely recognized by the method applied which was radioimmunoprecipitation. All kinds of infections were thus detected and it was possible to differentiate between cattle exposed or not exposed to challenge in the field, and further between protected animals and possible virus carriers.

Animals↗

PubMed1990

[The detection of bovine herpesvirus type 1 (BHV 1) using an intradermal test. II. Experimental studies].

A purified concentrated BHV1 antigen that had been tested in field trials was also tested under isolated conditions in BHV1 positive and negative cattle. The antigen proved to act specifically even after storage for 2 years at +4 degrees C or for 6 months at 37 degrees C. The best results were obtained when the test was read 48-72 hours after the injection, which is in agreement with the field trials. The increase in skin thickness decreased unless boosted by infection or vaccination gradually. The test is unsuitable to control a vaccination programme. There was no correlation between the increase in thickness and humoral antibody titers. Repeated application of the intradermal injection of the antigen did not result in seroconversion in seronegative cattle. The biological limits of the test evaluation are discussed.

Animals↗

PubMed1990

[Foot-and-mouth disease. Infection trial in cattle after a single vaccination].

Following an outbreak of FMD caused by an A5 strain in the spring of 1984, ten cattle were vaccinated with samples of the five commercial vaccines used for the vaccination campaign in that year, i.e. two animals per vaccine. Six weeks later the cattle were challenged by contact with animals inoculated with the virus strain isolated from the field outbreak. Seven of the ten cattle became severely ill, exhibiting the typical symptoms of FMD, one animal did not show any clinical symptoms, the remaining two weak ones that might have escaped recognition by the cattlemen. Virus could be recovered from the vaccinated animals from days 2 to 10 following contact with the non-vaccinated infected cattle. It was concluded that a single vaccination does not protect cattle against the isolate.

Animals↗

PubMed1989

Caprine arthritis encephalitis--a model for AIDS?

After an introductory description of the subfamily lentivirinae and the relations between Maedi/Visna virus and caprine arthritis encephalitis (CAE) virus und HIV, the present knowledge on CAE, including the clinical picture, pathological lesions, global distribution and transmission studies, is outlined. Other interesting features are briefly presented together with an explanation of why CAE could be used as a simple, nonprimate model in HIV research, especially for the evaluation of the effect of treatment compounds developed, of the efficacy of vaccines and the study of the effect of immunostimulants.

Acquired Immunodeficiency Syndrome↗

PubMed1989

[The detection of bovine herpesvirus type 1 (BHV 1) using an intradermal test. I. Field studies].

An intradermal test (delayed hypersensitivity test) for the diagnosis of BHV1 infection was evaluated in 791 cattle of 16 dairy farms. The skin reactions were compared with the results of serological examinations using a commercial BHV1 ELISA kit (Trachitest). As antigen concentrated, purified and inactivated BHV1 was used. The skin reaction (increase of the skin fold thickness) was used for the interpretation of test results. The best results were obtained with the control of the skin reaction on the third day after injection of the antigen. From 393 serologically BHV1 negative cattle with an age of more than 6 months 391 (99.5%) had a skin reaction up to 1.0 mm and 2 animals (0.5%) had a reaction of 1.3 and 1.9 mm, respectively. The mean increase of skin fold thickness was 0.2 mm. Out of 291 serologically BHV1 positive cattle with an age of more than 6 months 270 had antibodies from natural infection and, partially, from additional vaccination with inactivated BHV1 vaccine. 266 (98.5%) of these animals showed a skin reaction of more than 2.0 mm, in 3 animals (1.1%) a skin reaction up to 1.0 mm was observed and 1 animal (0.4%) had a reaction of 2.0 mm. The mean increase of the skin fold thickness was 6.3 mm. 21 animals had BHV1 antibodies only because of vaccination with inactivated BHV1 vaccine. Only 4 animals had a skin reaction of more than 2.0 mm. Among 107 animals with an age up to 6 months 30 were serologically BHV1 positive and 77 were BHV1 negative. In all animals the skin reaction was less than 1.0 mm, the mean was 0.2 mm.

Animals↗

PubMed1988

Vaccination to protect calves against infectious bovine rhinotracheitis.

A commercially available inactivated vaccine against infectious bovine rhinotracheitis (BHV1) was tested to assess its ability to immunise young seronegative calves and protect them against challenge with a virulent strain of BHV1. Calves showed seroconversion after one or two doses of vaccine. A two-dose and three-dose vaccination regimen each afforded calves significant protection against challenge as judged by the development of clinical symptoms. Vaccinated calves were on average 7 to 10 kg heavier than control calves 24 days after challenge, a statistically significant difference. Vaccination had no significant effect on the virus excretion pattern after challenge.

Animals↗

PubMed1988

[Enzootic bovine leukosis--a retrovirus disease].

After a short historical introduction and a description of some of the properties of the bovine leucosis (leukemia) virus (BLV) the natural pathways of transmission, for which most likely intact infected cells are a prerequisite, are described and the role of possible vectors mentioned. The iatrogenic transmission by needles, dehorning and perhaps even rectal examinations is discussed. Semen, embryo transfer, saliva, urine, faeces and breath do obviously not play any role in contrast to nasal secretions containing viable cells. It is pointed out that it is not inevitable to eliminate all seropositive cattle from the premises during an eradication programme provided some additional tests are carried out: determination of the white blood picture, the p 24 status and perhaps even proof of antigen production in short-term buffy coat cultures. Offspring of seropositive cattle requires some special attention and careful testing at certain intervals. The report according to which BVD/MD virus-infected cattle are superinfected with BLV leading to rather difficult situations is cited.

Animals↗

PubMed1987

Problems concerning the taxonomy of the 'Movar-type' bovine herpesviruses.

The inconsistency in naming and labeling bovine herpesviruses (BHVs), other than BHV types 1 and 2 (BHV-1 and BHV-2), found in the literature is reviewed. To resolve the confusion and misunderstanding caused by the use of BHV-3, BHV-4 and BHV-5 for the same kind of BHVs, the most used label BHV-4 is proposed for designating Movar-type BHVs (which also were named 'orphan viruses' or 'cytomegaloviruses').

Animals↗

PubMed1986