Background:Helicobacter pylori infection and related diseases outcome are mediated by a complex interplay between bacterial, host and environmental factors. Several distinct virulence factors of H. pylori have been shown to be associated with different clinical outcomes. Here we focused on vacA and cagA genotypes of H. pylori strains isolated from patients with gastric disorder.Objectives:The aim of this study was to determine the frequency of two toxins and genotypes of VacA toxin in patients referred to a central hospital in the west of Iran (Imam Reza hospital, Kermanshah) during 2011 - 2012.Patients and Methods:Samples were collected from patients infected with H. pylori. Gastric biopsy specimens from the stomach antrum and corpus were cultured. PCR analysis was performed for genotyping H. pylori vacA and cagA genes.Results:Helicobacter pylori was isolated from 48% (96/200) of patients with gastroduodenal disorders. In 81/96 (84%) cases, the cagA gene was present. Among different genotypes of vacA, two s1m2 and s2m2 genotypes were dominant with frequency of 39.5% and 50%, respectively. The frequency of the s1m1 genotype was 7.2% (7/96), which is much lower than elsewhere. H. pylori isolates with positive results for cagA gene and vacA s1m2 genotypes showed statistically significant correlation with peptic ulcer (s1m2 13/34 [38.2%] P = 0.003). However, isolates of H. pylori infection with cagA gene and vacA s2m2 genotypes were significantly associated with development of gastritis (s2m2 41/42 [97.6%] P = 0.000).Conclusions:About 90% of H. pylori strains potentially contained vacA s2m2 and s1m2 genotypes. Infection with H. pylori strain containing the cagA gene or the vacA s1m1 and s1m2 genotypes was associated with increased incidence of peptic ulcer disease (PUD).

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Abstract. Aberrant promoter methylation of genes is a common epigenetic alteration in colorectal cancer (CRC). In the present study, spastic paraplegia 20 (SPG20) promoter-methylated DNA, as a potential diagnostic biomarker, was investigated in plasma and tumor tissue samples from patients with CRC. To the best of our knowledge, the quantification of SPG20 promoter-methylated DNA in plasma samples remains unreported. SPG20 promoter methylation was investigated in 32 paired tumor and healthy adjacent tissues, 37 plasma samples from patients with CRC, and in 37 plasma samples from a healthy control group, using the MethyLight method. The percentage of methylated reference (PMR) values was determined for each sample, and the sensitivity and specificity of this unique biomarker were evaluated. PMR values were significantly higher in plasma samples from patients with CRC compared with in those from the control group (P<0.05). Plasma specimens from patients and healthy controls exhibited median PMR values of 7.7 (95% CI, 4.15-15.28) and 0.59 (95% CI, 0.14-1.12), respectively. Notably, the median PMR values were identified as 42.39 (95% CI, 27.69-72.26) and 3.61 (95% CI, 1.07-5.29) in tumor and adjacent healthy tissues, respectively. Using receiver-operating characteristics curve analysis, the area under curve (AUC) was demonstrated to be 0.984 for plasma samples, exhibiting a sensitivity of 81.1% and a specificity of 96.9%. Furthermore, the AUC was 0.996 for tissue samples, revealing a sensitivity of 93.8% and specificity of 99.96%.Results from the present study indicate that the identification of SPG20 promoter-methylated DNA in plasma is a potential diagnostic biomarker for the detection of CRC. Furthermore, the results demonstrate a satisfactory sensitivity and specificity, indicating the importance of SPG20 methylation as a novel noninvasive biomarker. IntroductionColorectal cancer (CRC) is one of the most common malignancies worldwide, accounting for an estimated 1.3 million new cases and >500,000 mortalities/year (1). CRC is the fourth leading cause of cancer-associated mortality worldwide, with a rapidly increasing incidence rate in the worldwide (2,3). In the Asian population, the annual prevalence rate of CRC has steadily increased over the past two decades (4). The Ministry of Health and Medical Education in Iran states that cancer is the third most common cause of mortality in Iran (5). Currently, the gold standard method for CRC detection is internal imaging of the colon with colonoscopy followed by a biopsy examination; however, it remains an invasive procedure with possible serious complications and limitations (6). Cancer is a multistep process resulting from a gradual accumulation of genetic and epigenetic changes to the genome (7). The methylation of 5'-C-phosphate-G-3' (CpG) islands has been suggested to be associated with gene silencing, serving an important role in cancer development (8,9). The aberrant promoter methylation of genes is a primary occurrence in the process of CRC carcinogenesis, whic...