Study of relationship between a strain of E.coli and colorectal cancer

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: 126 colon biopsies were obtained from colorectal cancer patients (60sample) and the healthy individuals (66samples) during Aug_Dec 2013. 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 12.2% and 4% 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

Drug Resistance Pattern of Toxigenic Clostridium difficileIsolated from Patients with Diarrhea to Conventional Therapeutic Drugs with Chronic

Background and Objectives: Clostridium difficile is a gram-positive obligate anaerobic bacillus. Accurate and rapid diagnosis of this bacterium as well as assessment of its drug resistance pattern are one of the important issues in controlling infections caused by C. difficile. The purpose of the present study was to detect toxicogenic C. difficile and to evaluate drug resistance pattern of these strains to routine therapeutic drugs.   Methods: A total of 68 samples were collected from patients hospitalized in hospitals of Qom province. All samples were rapidly cultured in the specialized CCFA Agar medium.After these procedures, the bacteria were used for DNA extraction and then PCR was performed on the cdd3 gene for definitive detection of the bacteria. Finally, the presence of A and B toxins’ genes was determined by PCR and resistance to metronidazole, vancomycin, and clindamycin, was determined by agar dilution method. Chi-square test was used to analyze the results.   Results: In this study, 6 isolates had A and B toxins, the highest antibiotic resistance was against clindamycin (45.45%) and metronidazole (36.36%), and all the isolates, were sensitive to vancomycin.   Conclusion: Drug resistance pattern in the obtained strains still introduces vancomycin as the treatment of choice