Investigation of the frequency and virulence genes of helicobacter pylori strains isolated from gastric biopsy from patients admitted gastroenterology clinics

Over half of the world's population is infected with Helicobacter pylori (H.pylori) and it is directly related to development of several gastroduodenal diseases, such as non-ulcer dyspepsia, peptic ulcer disease, gastric cancer and MALT (mucosa-associated lymphoid tissue) lymphoma. H.pylori infection is an important health problem, especially in developing countries. It has been proposed that the interactions between the host and environmental factors with bacterial virulance factors, play a significant role in determining prognosis of H.pylori infections. Several putative virulance genes, such as vacA and alleles, cagA, cagE, iceA and alleles and babA2 have been identified and may play important roles in the pathongenesis of H.pylori infections. The aim of this study was to determine the frequency and main virulance genes of H.pylori in the gastric biopsy specimens from 176 patients [gastric/duodenal mucosal damage (i.e. gastric/duodenal ulcus, gastric/duodenal erosion, duodenitis, gastritis, esophagitis; Group1, n=89) and no evidence gastric/duodenal mucosal damage (Group2, n=87) by endoscopic diagnosis] by using polymerase chain reaction (PCR). Patients main age was 37.93 ±15.31 and 59.7% were female. It have seen that, the frequency of H.pylori was 51.7% in all patients; 52.4% female and 50.7% male. The vacA allele and m2 allele were found in 70 (75.3%) and 58 (62.4%) of the 93 isolates. None of the strains was found to harbor the slc genotype. The frequencies of the cagA, cagE, iceA1, iceA2, babA2 genotypes amoung studied isolates were 88.2%, 96.8%, 33.3%, 35.5% and 88.2% respectively. The common vacA allelic combination seen in isolates from patients in Group1 were sla/m2 with 29 (53.7%) strains and sla/mla with 12 (30.8%) strains in isolates of Group2 patients.Consequently, vacAsla/m2 allelic combination was found statistically higher in Group1 patients than Group2. The most predominant genotypes combination were found to be associated vacAs1, cagA, cagE, babA2 and iceA1.