Influence of raffinose on the relative synthesis rate of K88 fimbriae and the adhesive capacity of Escherichia coli K88.

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.