INVESTIGATION OF Helicobacter pylori VIRULENCE GENOTYPE IN GASTRIC BIOPSIES BY PCR

Abstract

Objectives: Helicobacter pylori infections have been associated with the genetic diversity of their virulence factors; the virulence genotypes are valuable as a molecular marker in the diagnosis of patients with bacterial infections. Our main objective was to analyze the frequency and allelic genotype of vacuolating cytotoxin A (vacA) and cytotoxin-associated gene A (cagA) as well as investigate other virulence genes like outer inflammatory protein A gene (oipA) and a gene contact with the epithelium (iceA) of H. pylori. Methods:A total of 75 patients with gastritis and peptic ulcer diseases (PUDs) were selected to investigate H. pylori infections. 75 antrum biopsies were collected from these patients, and then genomic DNA was extracted from biopsies using the genomic DNA kit. Subsequently, the virulence genes of H. pylori were amplified using specific primers for vacA, cagA, cagE, iceA, and oipA by polymerase chain reaction (PCR).Results: A high prevalence of genes cagA (28.6%), vacAs1bm2 (44.68%), iceA2 (30.6%), and oipA (42.9%) was found, while vacA s2m1 and iceA1 genotypes was not found in our study. There was a significant correlation between the presence of cagA and cagE genotypes (p=0.02), suggesting that these two genes almost used together as a cagPAI integrity marker and the predominant cagA EPIYA motif was ABC (~650 bp) belong to Western cagA strains. The presence of the cagA + and vacA + genes was significantly associated with peptic ulceration (p≤0.001 at a level 0.01 and p≤0.044 at a level 0.05, respectively), whereas different iceA2 genotype was no statistically significant with clinical outcome. Patients with PUD more likely to have an oipA gene (61.9%) than those with gastritis (38.1%), p≤0.037, also the presence oipA gene was statistically significant with presence iceA2 and cagA, as well as the presence iceA gene was statistically significant with the presence vacA. Conclusion: Most H. pylori genotypes which associated with peptic ulcer and gastritis were moderate virulent strains, whereas the virulent strain which associated with peptic ulcer belong to Western cagA strains had vacAs1bm2 genotype, oipA and iceA2 genes that rarely induced gastric cancer in the middle region of Iraq.

Pangenome Analysis of Helicobacter pylori Isolates from Selected Areas of Africa Indicated Diverse Antibiotic Resistance and Virulence Genes

“…These genes are not only heterogeneously distributed but also exert varying degrees of virulence in the host [ 8 ]. In humans, these genes are associated with diseases like gastritis and peptic ulcers, predicates of gastric cancers [ 9 ]. As a result, the pathogen has been considered by WHO as a disturbing class one carcinogen worldwide.…”