Determination of the Prevalence and Genotypes of Helicobacter Pylori in the Gastric Biopsy Specimens from Patients with Gastroduodenal Patologies

H.pylori is an important infective agent which infects more than 50% of world population. It is reported that, the prognosis of gastric infection could be affected by the production of CagA and VacA toxins and allelic differences in coding genes of these toxins. While cagA+vacA+ strains called Type-I are responsible for more serious diseases such as chronic active gastritis, peptic ulcer and gastric cancer, cagA-vacA- strains are associated with asymptomatic carriage or non-ulcer dispepsia (NUD). The effects of vacA allelic combinations as well as Type-I strains on prognosis shows geographic differences in Western and Eastern populations. The relation between the clinical outcome and genotypes and allelic combination of causative strains isolated from patients with gastroduodenal disorder in different geographic regions in order to make true estimation on prognosis should be known. The aim of this study was to determine the prevalence and genotypes of H.pylori in the antral and corpus biopsy specimens from patients with gastritis and/or gastric ulcer (G/GU) and duodenal ulcer (DU) in our region. Two hundred thirty one patients with gastroduodenal complaints and who having endoscopic indications from University of Cukurova, Medical Faculty, Gastroenterology Department and Ministry of Health, Adana Cukurova Governmental Hospital, Gastroenterology Department were enrolled in this study. The DNA extractions from biopsy specimens were performed with QIAGEN tissue extraction kit. First, in order to demonstrate H.pylori colonisation, the spesific sequences of ureC gene were amplified with PCR (Polymerase Chain Reaction). Then, ureC-PCR-positive DNA templates were amplified by primers which target spesific sequences in order to detect cagA and vacA genes. The ?s? and ?m? alleles of vacA genes were investigated in all of vacA-positive DNA templates by PCR with allel spesific primers. Thus, in addition Type-I and Type-II genotypes, the allelic combinations of vacA gene of H.pylori strains were also determined. As a result, H.pylori ureC gene was found at least in one of the biopsy specimens from 201 (87%) patients; 72 (75%) female and 129 (95.6%) male. It have seen that, the prevalence of H.pylori was 82.9% in patients with G/GU and 95.9% in patients with DU. Of colonized strains 84.1% were cagA+vacA+ Type-I strains and prevalences of these strains in patients with G/GU and DU were 78.6% and 94.3% respectively. The most vacA allelic combination seen in Type-I strains was s1a/m1b with 47 (27.8%) strains and s1/m2 with 11 (36.7%) strains in Type-II strains. Especially, the presence of s1c allele in 59 (57.3%) strains from G/GU patients was striking. In conclusion, Type-I strains of H.pylori was found statistically higher in patients with DU than patients with G/GU. Besides, the prevalence of Type-I strains that contain s1a allel in patients with DU and s1c allele in patients with G/GU was found statistically higher than the other allelic types.