Objective: Shiga toxin-producing E. coli (STEC) strains are important foodborne pathogens. Significant outbreaks with STEC strains can be encountered, even if the geography, time or resources were different. The aim of our in silico study was to compare the virulance factors and phylogeny of STEC strains such as EDL933 and Sakai, which have been identified as an agent in important outbreaks in different parts of the world and whole genomic data were in open databases.

Method: Genomic NCBI data of eight strains were included in our study, including seven different STEC strains associated with significant epidemics in different parts of the world, and one super-shedder strain obtained from cattle feces.

Results: According to phylogeny analysis, the most similar strain to EDL933 strain was TW14588, with 96.4% similarity. The most distant similarity was Sakai strains with 79.2%. According to the virulence genes analysis; the presence of 333 genes that constitute virulence factors under nine headings were detected. In the first STEC origin, EDL933, 45% of all virulence genes were found to be active. Adherence genes such as Ecp, Elf, Hcp and toxin genes such as clyA were active in all strains except stx genes.

Conclusion: In our in silico study of comparative genomic analysis of STEC strains which are associated with outbreaks, it was determined that STEC strains used different virulence genes besides the stx gene. Indeed, they used certain virulence genes, even their sources, time and locations were different, in the pathogenesis.