raffinose and Swine-Diseases

Strains of Serpulina hyodysenteriae and Serpulina innocens produced a cell-associated sucrase activity when grown in a medium containing sucrose. S. hyodysenteriae B204 sucrase activity cleaved sucrose and, to a lesser extent, raffinose and had a pH optimum of 5.7 to 6.2. This is the first report of an inducible enzyme produced by either S. hyodysenteriae or S. innocens.

Topics: Animals; Brachyspira; Brachyspira hyodysenteriae; Enzyme Induction; Hydrogen-Ion Concentration; Intestine, Large; Kinetics; Raffinose; Spirochaetales Infections; Sucrase; Sucrose; Swine; Swine Diseases

The synthesis rate of K88 fimbriae relative to the rate of total protein synthesis was estimated during growth of a wild-type Escherichia coli Bd 1107/7508 (K88ac) in M9 minimal medium supplemented with glucose or raffinose as the carbon source. Rates of synthesis of fimbriae and total protein were analysed by immunoprecipitation and TCA precipitation of radioactive pulse labelled K88 fimbriae and E. coli K88 cells, respectively. In addition, the effect of raffinose on the in vitro adhesion of E. coli K88 cells to immobilized piglet ileal mucus was studied. The relative rate of K88 fimbriae synthesis increased gradually during log phase, reached maximum at late log phase, and thereafter decreased continuously. The use of raffinose as the carbon source, did not alter the relative rate of K88 fimbrial synthesis or the adhesive capacity of E. coli K88 cells, as compared to glucose.

Topics: Animals; Bacterial Adhesion; Escherichia coli; Fimbriae, Bacterial; Glucose; Ileum; Mucus; Radioactive Tracers; Raffinose; Swine; Swine Diseases

K88 antigen, and important virulence factor in porcine enteropathogenic Escherichia coli (EEC), can be transferred along with the ability to ferment the trisaccharide raffinose (Raf). The plasmids from a number of EEC strains that encode these two properties were isolated and characterized. In most strains the K88 and Raf genes were found on a single nonconjugative plasmid approximately 50 x 10(6) daltons in size. This plasmid core was conserved with only slight variation among the strains tested. In some transconjugants, larger conjugative plasmids were observed that were apparently recombinants between the Raf/K88 plasmid and a transfer fa(tor. Occasionally plasmids carrying only the raffinose fermentation genes arose by deletion of a deoxyribonucleic acid segment of about 20 x 10(6) daltons that included the K88 antigen gene(s).

Topics: Animals; Antigens, Bacterial; Base Sequence; Diarrhea; Escherichia coli; Genes; Genetic Linkage; Plasmids; Raffinose; Swine; Swine Diseases