In this study for detection of FI I fimbriae on pathogenic E. coli 300 strains isolated from chickens with colisepticemia or colibacilosis were grown and subjected 3-6 consecutive passages on TSA. Bacterial suspension were mixed with human erythrocyte suspension. For testing mannose-resistant hemagglutination (MRI-IA+) mannose was add to the erythrocyte suspension. Rabbit antifimbrial (F ll) serum used to detection of fimbrial antigen on indirect immunofluorescence technique. Crude fimbrial extracts from isolates prepared for immunodot and immunoblotting. Results indicate that five of these strains showed mannose resistant hemagglutination of human erythrocytes when grown at 37C on TSA. On immunofluorescence and immunodot. six strains reacted with Fl I antiserum. On immunoblotting, six strains demonstrated 18-kDa major fimbrial subunit wich reacted with specific Fl I antiserum. All of the fimbriated strains belong to 01 serogroup
)