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.

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.

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.

Immunofluorescent immunoglobulin differentiation of vibrio fetus antibodies from bovine cervico-vaginal secretions

Reports on discrepancies between local and systemic immunity started to appear about 50 years ago (cf. Tomasi & Bienenstock 1968). Protection against infections has been shown in many cases to be closely related to the antibody content of external secretions and more or less independent from the serum antibody level.