Isolation and characterization of immunogenic pili from avian pathogenic Escherichia coli

Bacteria, which attaches to different mucous membranes should have differing specificities of adherence in vitro. E. coli isolates recovered from different sources from poultry were characterized on the basis of haemagglutination patterns. Isolates causing high HA titer had large numbers of the pili but some well piliated strains were non haemagglutinating. In present study a modified technique for purification of avian E. coli pili was developed from the strains isolated from clinical cases of colibacillosis. After mechanical detachment from the bacterial cells, the pili were concentrated by precipitation with ammonium sulphate, dialyzed and solubelized in buffer containing deoxycholate. The fraction containing pilus was purified further by ultra centrifugation. Isolated pili migrated as a single band on sodium dodecyl sulfate poly acrylamide gel electrophoresis and these purified pili had a molecular weight of 18 Kda, which is immunodominant by Western blot.