Fariba Dastjani farahani - Department of Microbiology ,Qom branch ,Islamic Azad university ,Qom,Iran.
Shahla Mohammad Ganji - National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran.
Mojtaba Sohrabi - Department of Microbiology ,Qom branch ,Islamic Azad university ,Qom,Iran.

Background and Aim: The most important factors of colorectal cancer (CRC), as a multifactorial disease is bacterial infections. The studies showed that a certain type of infection with E.coli with PKS positive strain. This strain of bacteria can be promoted colorectal cancer in patients with inflammatory bowel disease (IBD) and ulcerative colitis (UC). In fact, the E.coli with PKS gene disrupt the cell cycle by producing the colibactin as secondary metabolites of bacteria, so leads to initiation and progression of colorectal cancer. The aim of this paper is describing the latest achievements regarding molecular study of this matter in the Iranian patients with CRC. Materials and Methods: ۱۲۶ colon biopsies were obtained from colorectal cancer patients (۶۰sample) and the healthy individuals (۶۶samples) during Aug_Dec ۲۰۱۳. After Isolating the E.coli and extraction of their DNA, duplex-PCR performed for PKs Island region. Results: The frequency of E.coli with Pks positive strains was ۱۲.۲% and ۴% in colorectal cancer patient and healthy individuals, respectively. Conclusions: The results of this study rather than similar studies in European countries showed the lower frequencies for E. coli with PKs positive strain in patients with CRC.

Escherichia coli, Colorectal Neoplasms, colibactin, اشریشیا کلی, کلی باکتین, سرطان کولورکتال