Phenotypic and genotypic characterization of isolated Shigella spp. from food based on IpaH gene and evaluation of their antibiotic patterns

Food is a vital substance which is important for human life. Although this vital matter could be a vehicle for transferring the microorganisms to human and Shigella is an important microorganism which could be cause of dysentery to human, the present study tried to isolate and characterized isolated Shigella from food.In this study 100 food samples including: 40 types of vegetables, 30 chicken, 20 minced meat and 10 fish have been collected. The samples were inoculated to gram negative broth and transferred to differential media such as MacConkey and Salmonella Shigella agar. Then the suspected colonies were identified using biochemical tests. Afterward, the isolates were characterized using ipaH gene by PCR technique. Furthermore, they were analyzed using serotyping techniques and the antibiotic susceptibility pattern were checked. Out of 100 foodstuffs the bacteria were detected only from vegetables. The isolates (n= 6) were confirmed by molecular techniques and all of them belong to the genus of Shigella. In addition the slide agglutination test showed that the isolates were belong to sh. dysentriae (n=1), Sh. sonnei (n=2), Sh. flexneri (n=2), and one non detectable. Furthermore, they showed different antibiotic pattern, as the isolate No.1 showed 100% sensitivity to the tetracycline and were resistant to the others Although foodstuffs are so important in transferring the microorganism, the monitoring of foods in market and greengrocery is necessary.