Lethality, hemagglutination and adhesion of Escherichia coli strains (Serotype 01) isolated in Morocco from chickens with colibacillosis

Six strains of Escherichia coli, isolated from chickens with colibacillosis and belonging to serotype 01, were studied. All of them were lethal for 1-day-old chicks and were strongly adherent in vitro. Hemagglutination tests showed a strong reaction to horst and chicken erythrocytes. This reaction was inhibited by the addition of 5% D-mannose and also by overnight incubation at 18 C. When the strains were heated at 65 C or at 85 C for 1 hr, agglutination of horse and chicken erythrocytes was conserved only at 65 C. Purification of the subunit of fimbriae by several cycles of solubilization-crystallization using MgCl2 gave good results. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed char the molecular weight for one strain was about 18.4 kD.