Detection of CagA, VacA, IceA1 and IceA2 virulent genes in Helicobacter pylori isolated from gastric ulcer patients

Abstract

Abstract Background Virulence factors of Helicobacter pylori including cagA, vacA, iceA and their association with clinical manifestation varied widely with different subpopulations. The objective of the study was to determine the prevalence of cagA, iceA1, iceA2, vacA, vacA s1/s2, vacA m1/m2, Western type cagA and East Asian type cagA virulence genes in H. pylori isolated from gastric ulcer patients and evaluate the association of these genes with gender, age, smoking and alcohol consumption. Methods Gastric biopsy samples from 172 patients were collected. H. pylori virulence genes, cagA, vacA, iceA1, iceA2, vacA s1/s2, vacA m1/m2, Western type cagA and East Asian type cagA were detected using polymerase chain reaction (PCR). Results Of the gastric biopsy samples collected, 48.3% of samples grew H. pylori. The vacA (68.7%) was the predominant virulence gene detected and associated with male patients and patients within the age group of 31–40 years. The cagA was the second most common gene detected and significantly associated with alcoholic patients. Conclusions H. pylori infection rate was 48.3% and was associated with patients who were smokers or had a history of smoking. The majority of our isolates were positive for any one of the virulence genes tested indicating that these isolates were highly virulent in nature.