[Infectious laryngotracheitis (ILT) in Switzerland: recent situation and thoughts about future possibilities for control]. / Die Infektiöse Laryngotracheitis (ILT) in der Schweiz: Aktueller Stand und Gedanken zu zukünftigen Bekämpfungsmöglichkeiten.

This short review highlights the characteristics of infectious laryngotracheitis, the diagnostic methods and the actual disease situation in Switzerland and other European countries. Recommendations for a future control policy are outlined.

Reduced intestinal colonisation with F18-positive enterotoxigenic Escherichia coli in weaned pigs fed chicken egg antibody against the fimbriae.

Newly weaned pigs were fed a basal diet containing either egg antibody against fimbriae F18 at a high or low level, control egg powder or no egg, and challenged with enterotoxigenic Escherichia coli with fimbriae F18. The challenge was repeated after termination of the antibody treatment. Antibody-containing egg powder was produced by vaccination of hens with semi-purified fimbriae of the two variants F18ab and F18ac. Pigs eating egg powder with antibody against the same fimbrial variant were fully protected, even if the vaccine for the hens was produced with a different serotype devoid of enterotoxins. The effect was dose-dependent. The high dose of antibody against the heterologous variant of fimbriae F18 reduced colonisation at a level which was not significant. Ingestion of egg antibody partially suppressed the build-up of anti-colonisation immunity. Oral application of egg antibodies offers a promising approach for the prevention of infectious diseases of the digestive tract.

[Salmonella gallinarum-pullorum infection of poultry: experiences in Switzerland]. / Die Salmonella gallinarum-pullorum-Infektion des Huhnes: Erfahrungen in der Schweiz.

37 Salmonella gallinarum-pullorum-strains were isolated from dead poultry between 1986 and 1996. All strains except one belonged to the biovar pullorum. 33 isolates were from fancy poultry flocks, four from backyard flocks. 10 of 12 chicks and 10 of 25 adult birds showed clinical signs of disease. The growing significance of fancy and backyard flocks as a reservoir for S. gallinarum-pullorum is emphasized in view of the increase in free range management of commercial layer and broiler flocks.

Designations F18ab and F18ac for the related fimbrial types F107, 2134P and 8813 of Escherichia coli isolated from porcine postweaning diarrhoea and from oedema disease.

The relatedness of the fimbriae produced by eight E. coli strains including type strains with F107 fimbriae, 2134P pili and colonization factor 8813 (preliminary F18), was examined. These strains had been isolated principally from pigs which were affected with postweaning diarrhoea or with oedema disease. The fimbriae were analyzed by means of electron microscopy, slide agglutination, immunofluorescence, immunogold labelling, immuno-diffusion, immunoelectrophoresis and western blot, molecular genetic techniques, and in vitro adhesion. The fimbriae of all the strains were long flexible filaments with a diameter not larger than 4.6 nm showing a zig-zag pattern. Results obtained by the serological techniques confirmed that the fimbriae possessed a common antigenic determinant designated 'a' in addition to a variant-specific determinant designated 'b' or 'c'. Immunoelectron microscopy demonstrated that the determinants 'a' and 'b' or 'a' and 'c' were localized along the same fimbrium. In immunoelectrophoresis, fimbrial extracts of selected strains yielded a single precipitation line towards the cathode. One single major subunit of approximately 15 kDa was recognised in western blots by antisera against the common antigenic determinant and the variant specific determinants. All strains possessed sequences related to gene fedA, coding for the major subunit of fimbriae F107. Two types of fedA-related subunit genes were differentiated, corresponding to the 'ab' and 'ac' types of fimbriae as defined by serological methods. The results demonstrated that F107 fimbriae, 2134P pili and colonization factor 8813 are related, and that two serological variants can be distinguished. We propose designations F18ab (for F107), and F18ac (for 2134P and 8813) in analogy to the nomenclature of F4 fimbriae.