No Detection of Streptococcus gallolyticus and Helicobacter pylori in Colorectal Cancer Tissue Samples in Shiraz, Iran

Background: Worldwide, colorectal cancer is the fourth most common cause of cancer-related deaths. Infectious agents have long been associated with development of gastrointestinal malignancies including colorectal cancer. Therefore, the aim of this study was to detect Streptococcus gallolyticus subsp. gallolyticus and Helicobacter pylori in colorectal cancer tissue specimens in comparison with healthy tissue specimens. Methods: A total of 210 tissue samples including 70 adenocarcinoma colorectal tissue, 70 adenomatous polyposis colorectal tissues, and 70 normal colorectal tissues were subjected to DNA extraction. The quality of the extracted DNA was confirmed by the amplification of a β-globin fragment using polymerase chain reaction (PCR). The presence of sod and glm genes were evaluated as Streptococcus gallolyticus and H. pylori presence markers by PCR method, respectively. Results: Out of 210 subjects, 112 were male and the rest were female. The age of our patients ranged from 22 to 87 with an average of 54 years. None of the samples in two studied groups were positive for the sod and glm genes. Conclusions: According to our results, S. gallolyticus subsp. gallolyticus and H. pylori might not be involved in colorectal cancer pathogenesis. More investigation on huge sample in different area might be clarified this results.