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Biomedical subjects

K B Pedersen

Publications and source records attributed to K B Pedersen.

At least 37 records · Page 2Linked to original sources
PubMed1981

Infection with RS streptococci in pigs.

RS streptococci were isolated from pigs that died in an outbreak of septicemia and meningitis in a Danish herd of swine. Most of the affected pigs were 7-9 weeks old. Experimental inoculation of SPF pigs with a culture of the streptococci isolated from the brain of a pig that had died during the outbreak showed that the bacterium was pathogenic for pigs. Out of 35 8-15-week-old pigs inoculated, nine developed arthritis and one died in septicemia. At necropsy, four of the pigs were found to have endocarditis. Blood cultures from pigs with endocarditis were constantly positive throughout the experiment, i.e., until the pigs died 5-7 weeks after inoculation. In vivo loss of capsular antigen was observed. A human strain of R streptococci isolated from a case of septicemia was also shown to be pathogenic for pigs.

Animals↗
PubMed1981

Studies on a haemolytic substance in Yersinia enterocolitica.

Yersinia enterocolitica serotype O3 was found to produce a haemolytic substance which could be released from the bacterial cells by sonic disintegration. The substance was non-dialysable, thermolabile, antigenic, and sensitive to trypsin. Chromatographic studies indicated a high molecular weight. Erythrocytes from different mammalian species differed in sensitivity to the haemolytic substance. Y. enterocolitica serotypes O8 and O9 produced no haemolytic substance.

Cations, Divalent↗
PubMed1981

The aetiological significance of Bordetella bronchiseptica and Pasteurella multocida in atrophic rhinitis of swine.

Experimental infection with either pure culture of Bordetella bronchiseptica or B. bronchiseptica and a toxin-producing strain of Pasteurella multocida was studied in newborn piglets from 26 sows. Pigs inoculated with B. bronchiseptica alone got mild lesions, whereas pigs inoculated with both organisms showed clinical and pathological signs of atrophic rhinitis, corresponding to the progressive natural diseases. The effect of vaccinating sows against B bronchiseptica during pregnancy was studied.

Animals↗
PubMed1979

Studies on Yersinia enterocolitica isolated from swine and dogs.

Yersinia enterocolitica serotype 03 was isolated from the colon contents of 27 (4.5%) of 599 bacon pigs on slaughter. Two (1.7%) out of 115 dogs were positive by culture for this human-athogenic serotype of Y. enterocolitica. A number of other serotypes of Y. enterocolitica were also obtained both from porcine and canine enteric contents (4b, 5a, 6, 7, 11, 12, 15, 17, 19, 26b, and non-typeable strains). All these serotypes are supposedly non-pathogenic for man and may possibly originate from the microflora of the environment. Haemolysis on bovine blood agar was observed for strains belonging to O-serotype 3.

Animals↗
PubMed1979

Studies on the interaction between different O-serotypes of Yersinia enterocolitica and HeLa cells.

Eighty strains of Yersinia enterocolitica were examined for their ability to invade HeLa cells. The following O-serotypes were found to be invasive: 1, 3, 4a, 4c, 5b, 8, 9, 15a, 18, 20, 21 and 22. Biochemically, these types are either indole-, aesculin-, and salicin-negative, or indole-positive but aesculin- and salicin-negative. Other serotypes of Y. enterocolitica did not invade HeLa cells. Biochemically, these non-invasive strains are indole-, aesculin- and salicin-positive. Also the non-sucrose-fermenting strains of O-serotypes 11 and 12 were non-invasive. The interaction with HeLa cells was not restricted to viable bacteria, since also bacterial cells inactivated by formalin or ultraviolet light could gain entrance to the HeLa cells. Heating of the bacteria to 100 degrees C for 30 min. completely inhibited their invasiveness. Monolayer cultures of porcine kidney cells were also invaded by strains which invaded HeLa cells.

Animals↗
PubMed1979

Occurrence of Yersinia enterocolitica in the throat of swine.

Yersinia enterocolitica serotype 0 3 was isolated from 84 (30%) of 282 throat swab cultures from bacon pigs at slaughter. Other serotypes of Y.e. were not isolated. All the isolations were made by the cold-enrichment method. The serum agglutinin titres against serotype 0 3 were low in most of the pigs examined. The rate of isolation of the organism increased with rising serum titre. In Denmark, Y.e. serotype 0 3 would appear to be a common inhabitant of the throat of swine.

Agglutinins↗
PubMed1978

Congenital ataxia and tremor with cerebellar hypoplasia in piglets borne by sows treated with Neguvon vet. (metrifonate, trichlorfon) during pregnancy.

In 1976--77 The State Veterinary Serum Laboratory received new-born pigs which had shown nervous disorders immediately after birth. In all the cases the sows had been treated with Nevugon vet. (metrifonate, trichlorfon) during pregnancy. In the majority of the affected litters the morbidity and lethality were 100 per cent. Analysis of the breeding data from some of the herds suggested that the period during which the fetuses are sensitive is rather narrow, i.e., approximately from day 45 to day 63. The disease was reproduced experimentally and it was concluded that oral treatment of pregnant sows with Neguvon vet. about the middle of the gestation period can result in severe nervous disorders in the piglets. Clinically the disease is characterized by ataxia and tremor, and corresponding to that there is a pronounced hypoplasia of the cerebellum and also a reduction in the size of the spinal cord.

Abnormalities, Drug-Induced↗
PubMed1977

[Actinobacillus infections in swine (author's transl)].

Actinobacilli infections in pigs are relatively rare. Most cases were septicaemic in the first week of life. With increasing age manifestations after generalized infections were characteristic, such as arthritis, polyarthritis, endocarditis, nephritis, osteomyelitis and embolic pneumonia. Of 34 porcine strains 33 were identified as A. equuli and only one was identical with A. suis. The justification of retaining this species is discussed.

Actinobacillus Infections↗
PubMed1977

Effect of vaccination of sows with Bordetella bronchiseptica on the incidence of atrophic rhinitis in swine.

Vaccination of pregnant sows with Bordetella bronchiseptica was performed in an SPF herd with clinical atrophic rhinitis. Agglutinins against the organism were induced in serum and colostrum by the vaccination. The antibody titres were generally higher in colostrum than in corresponding serum samples. The frequency at slaughter of turbinate atrophy (+, ++, +++) was lower among pigs from vaccinated sows (11%) than in pigs borne by unvaccinated sows (20%). In the control group a lower daily weight gain was observed in pigs with turbinate atrophy than in pigs with normal noses. The mean daily weight gain in pigs with turbinate atrophy borne by vaccinated sows was slightly lower than in pigs without atrophy of conchae, but the difference was not significant. A specific immunological prophylaxis might be an alternative to antibacterial treatment in herds where atrophic rhinitis is aetiologically related to B. bronchiseptica infection.

Animals↗
PubMed1976

Some factors influencing the haemolysis of Bordetella bronchiseptica.

Strain-dependent variations in the ability of Bordetella bronchiseptica to produce haemolysis on solid media exist. Haemolysis is strongest at an acid reaction and will not take place if the reaction is too alkaline. Peptone and glutamine inhibit haemolysis and favour growth. The vigorous growth rapidly produced an alkaline reaction which inhibits the haemolysis.

Amides↗
PubMed1976

Isolation of Yersinia enterocolitica from Danish swine and dogs.

Seventeen strains of Yersinia enterocolitica were isolated on examination of the caecal contents from 100 bacon pigs at slaughter. In another material consisting of 222 pigs with various diseases, the bacterium was found in 12 cases. Three out of 40 dogs were positive for the bacterium. Seven of the porcine and one of the canine strains belonged to serotype O 3, which is a human pathogen.

Animals↗
PubMed1975

The serology of Bordetella bronchiseptica isolated from pigs compared with strains from other animal species.

The serology of freshly isolated strains of Bordetella bronchiseptica from pigs and some other animal species was studied by the agglutination and agglutinin absorption tests. Differentiation was made between heat stable O-antigens and heat labile K-antigens. All the strains examined contained a common O-antigen (1). In addition, three heat stable antigens were detected. The heat labile antigens of freshly isolated strains were found to be very different. The major antigens 2 and 3 were not found in combination. A common weak K-antigen (1) was found in all strains. The pig strains were found to be serologically identical (0, 1, 2; K 1, 2). The same serotype was isolated from a rabbit. Another rabbit strain was found to be similar to a strain isolated from an SPF-rat (O, 1, 3; K 1, 3, 4). The antigenic pattern found in two cat strains was O 1, 3; K 1, 3. Typing of freshly isolated strains from pigs with monospecific factor sera confirmed that all the strains so far examined were serologically identical. This uniform serology hampers epidemiological studies of porcine bordetellosis by antigenic analysis. The occurrence of serologically different serotypes of B. bronchiseptica is of significance in the diagnostic bacteriology since the final diagnosis must be confirmed by a serological test.

Agglutination Tests↗