IDENTIFICATION OF EAEA PROTEIN IN THE OUTER-MEMBRANE OF ATTACHING ANDEFFACING ESCHERICHIA-COLI O45 FROM PIGS

We have previously reported that the production of attaching and effac ing lesions by Escherichia coli 045 isolates from pigs is associated w ith the eaeA (E. coli attaching and effacing) gene. In the present stu dy, expression of the EaeA protein, the eaeA gene product, among swine 045 E. coli isolates was examined. The majority (20/22) of attaching and effacing positive, eaeA(+) E. coli 045 isolates, but none of ten a ttaching and effacing negative, eaeA(-) or eaeA(+) isolates, expressed a 97-kDa outer membrane protein as revealed by sodium dodecyl sulfate -polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analys is. Amino-terminal amino acid sequencing demonstrated a high homology between this 97-kDa protein of swine E. coli 045 and the EaeA protein (intimin) of human enteropathogenic E. coli and enterohemorrhagic E. c oli. In addition, a serological relationship between the EaeA proteins of swine 045, rabbit (RDEC-1) and human (E2348/69) attaching and effa cing E. coli strains was observed. Our results indicate an association between expression of the EaeA protein and attaching and efficacing a ctivity among 045 E. coli isolates. The data also suggest an antigenic relatedness of the EaeA proteins of swine, rabbit, and human attachin g and effacing E. coli.