CLONING AND NUCLEOTIDE-SEQUENCE OF A GENE UPSTREAM OF THE EAEA GENE OF ENTEROHEMORRHAGIC ESCHERICHIA-COLI 0157-H7

A DNA segment located immediately upstream of the eaeA gene of enteroh emorrhagic Escherichia coli O157:H7 strain HA1 was cloned and sequence d. This segment contained an open reading frame encoding a predicted p rotein of 156 amino acids. A database search identified similar open r eading frames upstream of the eaeA gene in two other bacterial pathoge ns, i.e. enteropathogenic E. coli and Citrobacter freundii. The predic ted amino acid sequence of the enterohemorrhagic E. coli protein share d 96.8% and 94.2% identity with the enteropathogenic E. coli and C. fr eundii sequences, respectively. Because the open reading frame is loca ted within the locus of enterocyte effacement region of the E. coli ch romosome, a 'hot spot' for insertion of virulence factor genes, and sh ares high sequence homology with attaching and effacing EPEC and C. fr eundii, this protein may be associated with pathogenicity of E. coli O 157:H7.