Evolutionary dynamics of Helicobacter pylori cagA and vacA genes in Iran and their association with clinical outcomes

There is a relationship between specific genotypes of Helicobacter pylori cagA and vacA genes and the increased risk of peptic ulcer diseases and gastric cancer. These genes also possess strong patterns of geographical differentiation. The present study aims to determine the patterns of variation of the virulence genes in Iran and their association with clinical status. Sequence fragments for cagAand vacA were obtained from a total of 147 H. pylori isolates from diverse geographical and ethnic sources within Iran. We used phylogenetic methods to determine the patterns of allelic diversity, and the relationship between evolutionary lineages and clinical status. Phylogenetic analyses of Iranian cagA gene disclosed four lineages, whereas the vacA gene had two distinct lineages. The cagA lineage II showed extensive genetic diversity compared with lineage I. cagA lineages III and IV disclosed mixed ancestries with recombinant nucleotides that originated from lineages I and H Iranian strains with vac A lineage II genotype were significantly cagA+ [> 90%, p = 0.0] and correlated with a higher rate of peptic ulcers in infected individuals [p =0.003]. Most strains in the cagA lineage I showed a vacA lineage II genotype [p = 0.003] and significantly correlated with an increased risk of peptic ulcers in infected individuals [p = 0.022]. Strains with cagA lineage III genotype significantly correlated with gastritis [p = 0.0]. The increased level of allelic diversity in the virulence genes shows strong evolutionary dynamics, resulting in the emergence of new clonal genealogies of the cagA gene within Iran. Particular lineages of the Iranian cagA and vac A genes correlate with peptic ulcer diseases

comparative study of dental caries prevalence in 35-44 and 6-12 year old Iranian villagers and Afghan refugees living in villages of Isfahan Province of Iran

The most common disease of oral cavity is dental caries. Dental caries cause significant economical loss due to heavy expenses of dental treatment. The most important way to reduce this loss is attention to prevention measures. One of the criteria for evaluation of oral and dental health is DMFT index. The age groups of 35 to 44 and 6 to 12 years-old are the recommended age groups for determination of the DMFT index by the world health Organization. The aim of this study was to determine possible DMFT indices in Iranian villagers and Afghan refugees living in villages of Isfahan province aged 35 to 44 and 6 to 12 years. Two hundred and twenty women [110 Iranian and 110 Afghan ] and 256 men [128 Iranian and 128 Afghan] were examined for DMFT index. For reduction of the influence of Iran environment on the index, only the last five years refugees were examined. Only 20 cases [10 girls and 10 boys] of 6-12 years old Afghan children were available so they were compared with 20 [10 girls an d 10 boys] Iranian village children. None of the cases examined had the regular habit tooth brushing. T-student test was used for statistical analysis. DMFT indices were 3.7 +/- 2.6 and 0.6 +/- 1 in Iranian and Afghan boys respectively [t= 3.5] [significant correlation, P<0.01].DT, MT, FT and DMFT indices were 3.3 +/- 2.5, 3.9 +/- 3.8 [t=1.6], 5.5 +/- 6.9, 1.9 +/- 4 [t=5.2], 0.9 +/- 2.4, 0.2 +/- 0.7 [t=3.4] and 9.7 +/- 6.5, 5.7 [t=5.3] in Iranian and Afghan men and 4 +/- 3.2, 4.7 +/- 4 [t=1.3], 5.5 +/- 7.2, 2.1 +/- 3.3 [t=4.5], 2.7 +/- 3.2, 0.05 +/- 0.2 [t=8.6] and 12.2 +/- 6.7, 7 +/- 5.2 [t= 6.6] in Iranian and Afghan women, respectively. Except for DT [not significant, P<0.05] the difference were significant in all other cases [P<0.01]. Ten percent of Afghan women and 15.6% of Afghan men were caries free. This was not the case for Iranian villagers. In addition, 4.5% and 3.9% of Iranian women and men were edentulous respectively, while this was null for Afghans. Iranian villagers consumed more sugar than Afghans. The results showed the significant resistance to dental earis in Afghan people. This resistance could be correlated to genetic make up and feeding habits