Association among H. pylori virulence markers dupA, cagA and vacA in Brazilian patients

Abstract

BackgroundOnly a few Helicobacter pylori-infected individuals develop severe gastric diseases and virulence factors of H. pylori appear to be involved in such clinical outcomes. Duodenal ulcer promoting gene A (dupA) is a novel virulence factor of Helicobacter pylori that is associated with duodenal ulcer development and reduced risk for gastric carcinoma in some populations. The aims of the present study were to determine the presence of dupA gene and evaluate the association among dupA and other virulence factors including cagA and vacA in Brazilian patients. Gastric biopsies were obtained from 205 dyspeptic patients (100 children and 105 adults). DNA was extracted and analyzed for the presence of H. pylori and its virulence factors using the polymerase chain reaction method.ResultsPatients with gastritis tested positive for H. pylori more frequently. The dupA gene was detected in 41.5% of them (85/205); cagA gene was found in 98 isolates (47.8%) and vacA genotype s1/m1 in 50.2%, s1/m2 in 8.3%, s2/m2 in 36.6%, s2/m1 in 0.5% and s1/s2/m1/m2 in 4.4%. We also verified a significant association between cagA and dupA genes [p = 0.0003, relative risk (RR) 1.73 and confidence interval [CI] = 1.3–2.3]. The genotypes s1/m1 were also associated with dupA gene (p = 0.0001, RR: 1.72 and CI: 1.3–2.2). The same associations were found when analyzing pediatric and adult groups of patients individually.ConclusionOurs results suggest that dupA is highly frequent in Brazilian patients and is associated with cagA gene and vacA s1/m1 genotype, and it may be considered an important virulence factor in the development of gastric diseases in adults or children.

Virulence factors and antibiotic resistance of Helicobacter pylori isolated from raw milk and unpasteurized dairy products in Iran

“…Close association of cagA , vacA , iceA and oipA virulence factors with interleukin 8 (IL-8) production, cytotoxin production, gastric epithelial cells adhesion, inflammatory effects, vacuolization and apoptosis in gastric epithelial cells has been previously observed [ 25 – 28 ]. High prevalence of cagA , vacA , iceA and oipA virulence factors in cases of gastritis, peptic ulcer and gastric cancer has been reported in the United States, Turkey, Japan and Brazil [ 29 – 32 ]. Since H. pylori isolates in our study harbored cagA (76.6%) and vacA (75%) genes, consumption of milk and dairy products contaminated with virulent strains may provoke duodenal ulceration, gastric mucosal atrophy and gastric cancer.…”

Bioactive Components in Fish Venoms

“…In stonefish, the venom gland is more advanced, with the distal end attenuated to form a duct-like structure within the spine groove through which the venom may travel before being expelled from the spine [ 24 ]. Envenomation occurs when mechanical pressure is applied to the venom apparatus, causing the venom to be expelled through the canaliculated spines and into the victim [ 28 ]. Venomous fish lack musculature associated with their venom apparatus, and are therefore unable to voluntarily control the release of their venom.…”

Plasticity Region Genes jhp0940, jhp0945, jhp0947, and jhp0949 of Helicobacter pylori in Isolates from Mexican Children

“…Only one report has found an association between jhp0947 and the presence of cag PAI . Nevertheless, we found an association between the virulence factors cag A and cag PAI with dup A, consistent with one study of children and adults in Brazil . These facts indicate that the virulence factors act independently of the presence of jhp0940 , jhp0945 , jhp0947 , or jhp0949 .…”