Prevalence of Helicobacter pylori vacuolating cytotoxin A gene as a predictive marker for different gastrodoudenal diseases

Helicobacter pylori [H. pylori] has several virulence factors such as vacA and cagA genes. Mosaicism in vacA alleles with two distinct families of vacA signal sequences [s1, s2] and two distinct families of middle region alleles [m1, m2] is reported. The aim of this study was determination of H. pylori vacA allelic types in Chaharmahal and Bakhtiyari province, Iran and their correlation with six different gastroduodenal diseases. This cross-sectional descriptive study was performed on 200 antral gastric biopsy specimens that were obtained from patients undergoing upper gastrointestinal tract endoscopy in Hajar Hospital of Shahrekord. Initially, H. pylori strains were identified by rapid urease test [RUT] and ureC primers, and thereafter, we used seven specific primers for detection of vacA genotypes. Statistical analyses were used to find their relationship to gastric disorders. The frequency of the vacA alleles, s1a/m1a, s1a/m1b, s1a/m2, s1b/m1a, s1b/m1b, s1b/m2, s1c/m1a, s1c/m1b, s1c/m2, s2/m1a, s2/m1b and s2/m2 were respectively, 27[16.46%], 8[4.87%], 45[28.43%], 7[4.26%], 5[3.04%], 10[6.09%], 12[7.31%], 4[2.43%], 18[10.97%], 6[3.65%], 0 and 22[13.41%]. s1a/m2 strains were the most prevalent strains in this region and there was a considerable relationship between s1a/m1a, s1a/m2, s2/m2 and s1c/m1a with some gastric disorders. As the findings are different from other regions of the world, extended molecular epidemiologic investigations are recommended in other cities of Iran