The procedure of DNA extraction of E. coli O157 isolates was done in the same way as described before . Partial 16S rDNA was amplified using the universal oligonucleotides primers Forward: S-D-Bact-0341-b-S-17 and Reverse: S-D-Bact-0785-a-A-21 adopted from . Universal primers were used as this study was part of a project titled “Genetic authentication of bacterial isolates from meat and milk products in Libya and establishing the Food-borne Libyan-type Bacterial Collection (FLBC).” Therefore, the entire project was not focused on E. coli but also for many other bacterial isolates (total of 330 PCR products were sequenced) from milk and meat products in Libya; hence, the universal primers were used to detect all other bacterial isolates in all samples. The amplified 16S rDNA PCR fragment (464 bp) was excised from the gel, and the DNA was extracted from the gel using GF-1 Ambi Clean kit (Cat. #GF-GC-100, Vivantis, Malaysia). The purified 16S rDNA amplicons were then sequenced in Istituto Zooprofilattico Sperimentale della Lombardia e dell Emilia Romagna, Brescia, Italy, as described before . All sequences will be submitted to the GenBank in the near future once completing of all project studies.