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Biomedical subjects

R Gudding

Publications and source records attributed to R Gudding.

16 recordsLinked to original sources

Seroepidemiological studies of Borrelia burgdorferi infection in sheep in Norway.

An enzyme-linked immunosorbent assay for antibodies to Borrelia burgdorferi in sheep was established. The assay was used in a seroepidemiological survey in which serum samples from 327 Norwegian rams were screened for antibodies to B. burgdorferi. These rams were randomly chosen, clinically healthy animals from all parts of Norway. They came both from areas where Ixodes ricinus is common and from areas where the tick has not been found. The age of the animals varied from 0.5 to 7.5 years. Sera from 10% of the animals tested were seropositive by the enzyme-linked immunosorbent assay, with the percentage of positive animals varying from 0 to 20% between counties. The distribution of seropositive animals was generally in good agreement with the known distribution of I. ricinus, with the highest proportion of seropositive animals being in southern coastal areas of Norway. There were some exceptions, however, because seropositive animals were also found in areas where the tick has not been recorded. The majority of animals appeared to become infected during the first 2 years of life, with 12% of animals that were 1.5 years old being seropositive. The animals were all healthy at the time of serum sampling, and the clinical significance of B. burgdorferi in sheep is still uncertain.

Age Factors

Economic analysis of vaccination applied to ovine listeriosis.

An economic model for determining whether vaccination against a disease would be beneficial financially on individual farms is proposed; it is based on four pieces of information: the costs of a disease case including its treatment, the cost of vaccinating each animal including veterinary fees, the expected incidence of the disease, and the efficacy of the vaccine. The model was applied to ovine listeriosis, which is a serious disease problem in Norway. Vaccination appeared to be beneficial for the average sheep flock of 100 ewes which might expect two or more cases of listeriosis per year. Furthermore, the model suggests the ratio of the price of a single vaccination to the cost of a disease case can be used to plan more efficient vaccine field trials.

Animals

Immunisation against ringworm in cattle.

Immunisation against dermatomycoses in cattle was introduced in Gausdal, Norway, in 1979. A programme was implemented in which a six-year period of mandatory vaccination of all cattle was followed by vaccination on a voluntary basis. The prevalence of infected herds fell from 70 per cent in 1979 to 0 per cent in 1987. During the last five years, no newly infected herds have been registered in Gausdal. Proper disinfection of premises, the isolation of infected animals and other hygienic measures contributed to the successful result.

Animals

Immune response after immunization with an experimental Toxoplasma gondii ISCOM vaccine.

Mice were immunized with ISCOM preparations of tachyzoites from two different strains of Toxoplasma gondii. The antibody response and the cellular response, as measured in vitro, were comparable with those found in chronically infected mice. When challenged with virulent T. gondii tachyzoites, all the immunized mice died, whereas all the chronically infected mice survived. However, the immunized mice generally survived longer than non-immunized animals.

Animals

Clinical chemical constituents in relation to liver amyloidosis in serum-producing horses.

Serum activities of gamma-glutamyl transferase (GGT), alkaline phosphatase (AP), aspartate aminotransferase (AST), and concentrations of total bilirubin and total bile acids were screened during a 5 year period in 27 horses used for production of hyperimmune serum. The horses investigated were regularly immunized with live cultures of the endotoxin-releasing bacteria Escherichia coli or Pasteurella multocida, the individual animals having undergone such treatment for periods varying from 2 weeks to 10 years. In a majority of the horses, GGT-activity had increased within 6 to 7 years of first having undergone immunization. Constantly high values seemed to co-incide with the presence of advanced liver amyloidosis, as demonstrated by histopathological examination after slaughter. The AP activity was also increased but only moderately compared with GGT. Individual values more than 10-fold greater than the upper reference limit were recorded for GGT, while the highest AP values were less than double the upper reference limit. Activity of AST and bilirubin concentrations remained unaffected, whereas the concentration of total bile acids rose after 6 to 7 years of immunization compared to the baseline value. It is concluded that the determination of serum activities of GGT may serve as a practical routine test for the evaluation of liver amyloidosis status in serum horses.

Alkaline Phosphatase

Characterization of Vibrio anguillarum and closely related species isolated from farmed fish in Norway.

A total of 264 bacterial strains tentatively or definitely classified as Vibrio anguillarum were examined. The strains were isolated from diseased or healthy Norwegian fish after routine autopsy. With the exception of five isolates from wild saithe (Pollachius virens), the strains originated from nine different species of farmed fish. The bacteria were subjected to morphological, physiological, and biochemical studies, numerical taxonomical analyses, serotyping by slide agglutination and enzyme-linked immunosorbent assay, DNA-plasmid profiling, and in vitro antimicrobial drug susceptibility testing. The results of the microbiological studies were correlated to anamnestic information. The bacterial strains were identified as V. anguillarum serovar O1 (n = 132), serovar O2 (n = 89), serovar O4 (n = 2), serovar O8 (n = 1), and not typeable (n = 1) as well as Vibrio splendidus biovar I (n = 36) and biovar II (n = 1), Vibrio tubiashii (n = 1), and Vibrio fischerii (n = 1). V. anguillarum serovar O1 or O2 was isolated in 176 out of 179 cases of clinical vibriosis in Atlantic salmon (Salmo salar). V. anguillarum serovar O1 was the only serovar isolated from salmonid fish species other than Atlantic salmon, while V. anguillarum serovar O2 was isolated from all marine fish suffering from vibriosis. A 48-Mda plasmid was isolated from all V. anguillarum serovar O1 isolates examined. Serovar O2 isolates did not harbor any plasmids. Resistance against commonly used antibiotic compounds was not demonstrated among V. anguillarum isolates. Neither V. splendidus biovar I nor other V. anguillarum-related species appeared to be of clinical importance among salmonid fish.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

A method for monitoring antibodies against staphylococcal DNases.

When small amounts of DNase produced by Staphylococcus aureus, S. intermedius or S. hyicus were added to Toluidine Blue DNA Agar (TDA), a medium for demonstration of staphylococcal antiDNases was produced. By applying this medium in microtitre plates, a test system for titration of staphylococcal antibodies in serum samples was developed. A colour change from blue to pink could be observed when the DNase was allowed to act, i.e. when no staphylococcal antiDNases were present in the samples. When serum with neutralizing antibodies were applied, no colour change developed. An end-point could easily be demonstrated in dilutions of the serum. A description of the method, including certain of its limitations is given.

Animals

Immunisation against infections caused by Listeria monocytogenes in sheep.

Immunisation against listeriosis in sheep using a live, attenuated vaccine was introduced in Norway in 1984. Since then 65,000 to 80,000 animals have been vaccinated annually. Information obtained by a questionnaire showed that the incidence of listeriosis decreased from approximately 4.0 per cent before the introduction of the vaccine to 1.5 per cent after vaccination started. The incidence of abortions was 0.7 per cent in vaccinated flocks compared to 1.1 per cent in unvaccinated flocks. There were a few adverse reactions in the vaccinated sheep.

Animals

In vitro antibiotic sensitivity test of Staphylococcus aureus isolated from mastitic milk.

The antibiotic susceptibility of 2297 strains of Staphylococci aureus isolated from mastitic milk has been tested. The percentage of strains of S. aureus "resistant" to penicillin was 16.5%. Approximately 97% of these strains were susceptible both to tetracyclines and sulfonamides. The frequency of "resistant" strains is in good agreement with the results from a comparable survey done ten years ago. In this investigation, however, the strains of S. aureus showed great variation in their sensitivity to penicillin according to their geographical origin. Thus, the percentage "resistant" strains within counties varied from a minimum of 9.26 to a maximum of 53.05.

Animals