Roghayeh Gholizadeh doran mahalleh - Faculty member, Department of Laboratory Sciences, Faculty of Medicine, Islamic Azad University Zahedan,,Zahedan, Iran.
Nadia Kazemipour - Assistant Professor, Faculty, Islamic Azad University Kerman, Department of Microbiology, Kerman, Iran.
Farokh Rokhbakhsh zamein - Assistant Professor, Faculty, Islamic Azad University Kerman, Department of Microbiology, Kerman, Iran.

Background, consumption of contaminated food and water, lack of personal hygiene, reduce stomach acid changes the normal flora of the bowel, taking antibiotics and immune deficiency that weakens the intestinal defense mechanisms and the pathogenesis is. The purpose of this article is an overview of bacterial infections of the gastrointestinal tract. This study literature in this field, especially new articles are compiled based on li-brary studies. virulence factors in the human gastrointestinal tract, bacteria: Helicobacter, Campylobacter, E.coli, Salmonella, Shigella, Vibrio cholerae, Yersinia. Virus species are: Rotaviruses, enteric Adenoviruses, Norak. Para-sites: lamblia, Entamoeba histolytica. worms: Tapeworms, pinworms (the disease), Nematodes.

Enterobacteriaceae, infections, gastrointestinal microbiology