NEW ADHERENT FORM OF AN ATTACHING AND EFFACING ESCHERICHIA-COLI (EAEA-) TO THE INTESTINAL EPITHELIAL-CELLS OF CHICKS(, BFP)

The adherent site of ''attaching and effacing Escherichia coli'' (AEEC ; O103: H-, SK-1 strain) on the intestinal epithelial cells of chicks infected naturally and experimentally was ultrastructurally investigat ed. The eaeA gene was detected by polymerase chain reaction in the SK- 1 strain of E. coli isolated from the intestinal content of a chick in fected naturally, however, the bundle-forming pilus gene could not be detected. The SK-1 strain (bfp-) of AEEC could attach to the intestina l epithelial cell and induce attaching effacing lesions in the intesti ne of chicks. Transmission electron microscopy revealed numerous pilus -like microfilaments in the space between colibacilli and the membrane s of the intestinal epithelial cells. The present study suggests that SK-1 strain (eaeA+, bfp-) may attach closely to the intestinal epithel ial cells by a novel adhesin different from bfp.