ADHERENCE PILI OF PATHOGENIC STRAINS OF AVIAN ESCHERICHIA-COLI

Fifty strains of Escherichia coli isolated from coliseptcemic chickens in Londrina, Brazil, were examined for presence of gene sequences for pil and pap, hemagglutination, and adherence to chicken tracheal cell s. Forty-one strains were pil(+) and 22 of these showed mannose sensit ive (MS) hemagglutination (MSHA) of guinea-pig erythrocytes, indicatin g that they possessed only type 1 pill. Seven strains were pap(+) and 6 of these caused mannose resistant (MR) hemagglutination (MRHA) of hu man erythrocytes. Twenty-four strains (17 of which caused MSHA) showed MS-adherence to chicken tracheal cells and the remaining 26 showed MR -adherence. The former typically adhered to the mucus layer whereas th e latter usually adhered to the mucosal epithelium. It is concluded th at MS adherence to chicken tracheal cells is correlated with expressio n of type 1 fimbriae and that MR-adherence to chicken tracheal cells c annot always be attributed to P pill. (C) 1997 Elsevier Science B.V.