Phylogenetic tree was constructed using neighbor-joining algorithm (http://www.phylogeny.fr/simple_phylogeny.cgi) of partial 16S rDNA nucleotides sequence to show the phylogenetic relationships between local isolates sequences and those between the sequences of E. coli O157: H7 (Sakai and FRIK944 strains), Shigella flexneri, Salmonella Typhi, Proteus vulgaris, and Pseudomonas aeruginosa available in the GenBank, the National Institutes of Health genetic sequence database.