Frequency of significant virulence genes in gastric biopsies of Helicobacter pylori-positive patients with gastritis (original) (raw)

Determination of Helicobacter pylori Virulence Genes in Gastric Biopsies by PCR

ISRN Gastroenterology (Print), 2013

The aim of this study was to identify the presence of H. pylori in biopsy specimens from symptomatic patients by PCR. In addition, the rate of cagA, vacA, iceA1, and iceA2 virulence genes was determined. Materials and Methods. One hundred antral gastric biopsy specimens were collected during endoscopy from patients suffering from gastroduodenal symptoms. The samples were collected by the gastroenterologists in their own clinics in Ramallah, Palestine. DNA was extracted from the biopsies and subsequently used for PCR identification of H. pylori and the virulence genes using specific primers. Results. The rate of positive H. pylori in the collected biopsies was 44%. The rates of the virulence genes in this sample: cagA, vacA, iceA1, and iceA2 were 65.9%, 40.9%, 63.6%, and 84.1%, respectively. Conclusion. The iceA2 gene was the most frequent in this study. Much research is necessary to determine the presence of an association of this gene with gastric pathology. Variation in the rates of the iceA gene in different countries is a strong indication of its geographical distribution. This study would provide important information regarding the prevalence of virulence genes (vacA, cagA, iceA1, and iceA2) in H. pylori strains in the sample tested in this country.

Detection of Helicobacter pylori vacA , cagA and iceA1 virulence genes associated with gastric diseases in Egyptian patients

Egyptian Journal of Medical Human Genetics, 2017

Background: Helicobactor pylori (H. pylori) virulence markers would be useful to predict peptic ulcer disease (PUD) or gastric cancer. Aim: In Egypt, since inadequate data are present regarding H. pylori virulence-related genes in different age group patients with gastro-duodenal diseases, it becomes crucial to study the clinical status of cagA, vacA and iceA1 genotypes of H. pylori strains recovered from patients with dyspepsia. Subjects and methods: The study included 113 dyspeptic patients who were exposed to upper gastrointestinal endoscopic examination. Four antral biopsies were obtained from each patient for the analysis of H. pylori infection by rapid urease test and detection of 16S rRNA. Results: Sixty (53.1%) patients were confirmed to be infected with H. pylori. Upon endoscopy, gastritis was revealed in 27 patients (45%) and10 patients (16.7%) had PUD. Of the 60 H. pylori strains, 39 (65%) had at least one virulence gene. Six different genotypic forms were recognized; vacA (9/60), iceA1 (1/60), vacA/cagA (7/60), vacA/iceA1 (13/60), vacA/cagA/iceA1 (8/60) only one of cagA/iceA type and we could not detect cagA. The overall vacA, iceA1and cagA genes identified were 61.6%, 38.8%, 26.6% respectively, by PCR-based molecular testing. The vacA gene status was highly significant related to gastritis patient (P 0.036). The vacA s1m1 and s2m2 alleles were significantly found in 50% of H. pylori infected patients with PUD and with gastritis 57.1% respectively (P 0.01). Conclusion: In conclusion, the main genotype combinations in the studied Egyptian patients were; vacAs2m2/iceA1, vacAs1m1/cagA, mostly associated with gastritis, and vacAs1/cagA/icA, mainly in PUD. The less virulent (s2, s2m2) H. pylori genotypes were found in patients aged over 43 years.

Determination of Helicobacter pylori virulence-associated genes in duodenal ulcer and gastric biopsies

Medical Journal of the Islamic Republic of Iran

Background: Helicobacter pylori (H. pylori or Hp) has been strongly associated with the peptic ulcer diseases, chronic gastritis, ulcers, and gastric cancer. Genes associated with pathogenicity have been designated for H. pylori, and some of them appear to be related to more severe clinical consequences of the infection. The present study was conducted to determine cagA, vacA, cagE, iceA1, oipA, and iceA2 genes in H. pylori strains isolated from gastroduodenal patients, who referred to Shariati hospital in Tehran, Iran. Methods: Gastric biopsy specimens were collected during endoscopy from patients, who referred to the Shariati hospital in Tehran, Iran during January and November 2015. After isolation of H. pylori from the biopsy culture, genomic DNA was extracted and subsequently used to identify H. pylori and virulence genes using specific primers. Results: The isolation rate of H. pylori strains was 65.7% (169/257). The frequency of cagA, vacA, cagE, iceA1, oipA, and iceA2 was 143 (% 84.6), 169 (100%), 131 (77.5%), 97 (57.3%), 89 (52.6%), and 72 (42.6%), respectively. Conclusion: In this study, a significant difference was observed between investigated genes and strains isolated from PUD and GC patients (p<0.05).

Study of Virulence Genes Cag A and Vac A in Helicobacter pylori Isolated from Mansoura University Hospital Patients by Multiplex PCR

International Journal of Current Microbiology and Applied Sciences, 2016

Helicobacter pylori (H.pylori) is associated with various upper gastrointestinal tract disorders. Virulence genes are cofactors for the pathogenicity of H.pylori. The aims of the present study were to study the prevalence of cagA and vaca genes among H.pylori strains isolated from patients with upper gastrointestinal disorders requiring endoscopic examinations and to relate the presence of these virulence genes to the clinical presentations of those patients. The study included eighty two patients complaining of upper gastrointestinal disorders requiring endoscopic examinations Biopsies were obtained from each subject and specific culture for H.pylori were performed. Multiplex polymerase chain reaction was performed for isolated H.pylori strains to identy the presence of cagA and vaca genes. Their complaints were mainly gastric ulcer (40.2%), simple gastritis (32.9%) and duodenal ulcer (26.8%). Culture of H.pylori was positive in 60.9% of samples. Virulence gene cagA was identified in 62% and VacA in 58% of H.pylori isolates. All strains that harbor vacA had also cagA with two isolates with cagA gene alone. H.pylori was isolated in significant higher percentage (P=0007) from gastric ulcer (93.9%) then duodenal ulcer (45.5%) than simple gastritis (22.2%). Both cagA and vacA were significantly (P=0.0001) associated with gastric ulcer (51.5% & 60.6% respectively) compared to other clinical finding. From this study we can conclude that H.pylori is a common pathogen associated with upper gastrointestinal tract mainly with gastric ulcer. H.pylori strains responsible for gastric ulcer were significantly harboring the caga and vaca virulence genes. These genes may predispose to severe gastric disorders. Extended large scale studies are required to find the pathogenesis of these genes in Egyptian population.

Study of the clinical relevance of Helicobacter pylori virulence genes to gastric diseases among Egyptian patients

Arab Journal of Gastroenterology, 2016

Background and study aims: Helicobacter pylori infection is common in Egypt. It has been associated with gastritis, ulcers and it is a risk factor for gastric cancer. We aimed to study the correlation between the presence of H. pylori virulence factors and the histopathological and endoscopic findings in gastric biopsies. Patients and methods: Gastric biopsies from thirty seven patients scheduled for diagnostic endoscopy in Cairo University hospital were included in the study. All gastric biopsies were subjected to histopathological examination and PCR assay for detection of 16S rRNA gene to diagnose H. pylori infection, detection of H. pylori virulence factors by PCR for cagA and vacA genotypes and serological analysis of H. pylori (cagA, vacA, P25, and P19) IgG antibodies by immunoblot assay were done. Results: H. pylori infection was detected in 23 (62.2%) cases by histopathology while 28/37 (75.7%) were positive for H. pylori 16S rRNA gene by PCR. By PCR seventeen samples out of 37 (45.9%) were positive for cagA gene and five (13.5%) for cag empty site gene. Conclusion: The most common vacA genotype identified was vacA s2m2 genotype in 10 (27.02%). No statistical correlation was found between IgG antibodies against different antigens of H. pylori virulence factors (cagA, vacA, p25, and p19) and the degree of gastritis except for IgG antibodies against the UreA antigen.

Detection of, cagA and vacA Helicobacter pylori Virulence Genes in Gastric Biopsies of patients with Gastroduodenal disease using Polymerase chain reaction (PCR) technique

Diyala Journal For Pure Science

The objective of current study was to detect the prevalence of Helicobacter pylori by identifying 16SrDNA and to determine the virulence genes (ureA, cagA and vacA) in biopsy specimens from patients suffering gastroduodenal disease using polymerase chain reaction (PCR). Forty samples were obtained by gastroenterologists during endoscopy from gastric antral of suspected individual attending endoscopy unit at Baqubah Teaching Hospital, Diyala, Iraq, during the period from September 2015 to February 2016. According to the endoscopic finding the patients were allocated into four groups of gastroduodenal diseases and control, which include gastritis (GS), duodenal ulcer (DU), gastric ulcer (GU), gastric cancer (GC), their rates were 30% (12), 20% (8), 17.5% (7), 7.5% (3) and 25% (10), respectively. DNA was extracted from the biopsies and subsequently used for PCR detection of H. pylori and the virulence genes using specific primers. The results shows that 60% of samples were positive for H. pylori, of these positive samples, 91,66%, 66.66%, and 48.83%, were shown to have the virulence genes, ureA, cagA, and vacA, respectively. It is important to mention that cagA shown the highest prevalence rate in gastric cancer cases in comparison with vacA gene. further studies are required to study the link between cagA gene and Detection of, cagA and vacA Helicobacter pylori Virulence Genes in Gastric Biopsies of patients with Gastroduodenal disease using Polymerase chain reaction (PCR) technique

Genotyping of Helicobacter pylori Virulence Genes cagA and vacA: Regional and National Study

International Journal of Microbiology

Helicobacter pylori (H. pylori) plays a crucial role in the pathogenesis of gastritis, peptic ulcer, and gastric cancer. The presence of pathogenicity islands (PAI) genes contributes to the pathogenesis of many gastrointestinal disorders. Cytotoxin-associated gene A (cagA) and vacuolating cytotoxin gene (vacA) are the most known virulence genes in H. pylori. So, our aim was to study H. pylori virulence genes’ role in gastric disorders pathogenesis. Our study included 150 adult patients who suffered dyspeptic symptoms and were referred to the GIT endoscopy unit. Gastric biopsies were attained for rapid urease test (RUT) and histopathological examination, and multiplex PCR technique for detection of virulence genes was performed. It was found that 100 specimens were (RUT) positive, of which sixty samples (60%) were PCR positive for H. pylori ureC gene. The vacA and cagA genes were identified in 61.6% and 53% of H. pylori strains, respectively. Only 5 cases were vacA-positive and cagA-...

Detection of Helicobacter pylori cagA gene in gastric biopsies, clinical isolates and faeces

Indian journal of medical microbiology, 2006

Helicobacter pylori infection is common in the developing countries. The cagA gene is a marker of pathogenicity island (PAI) in H. pylori . The aim of this study was to determine the prevalence of cagA among dyspeptic patients in Bahrain directly from gastric biopsy and stool specimen. A total of 100 gastric biopsy samples, 16 clinical isolates and 44 faecal specimens were collected from Bahraini adult dyspeptic patients. cagA gene of H. pylori was assessed using polymerase chain reaction (PCR). The cagA gene was detected in 59 (59%) from biopsy specimens, 10 (62%) clinical isolates and in 10 (22.7%) faecal specimens. The detection of cagA positive H. pylori was significantly higher in patients with duodenal ulcer (80%) compared to those with other endoscopic finding (42%) (P < 0.05). Using PCR to detect cagA gene directly from biopsy is a rapid and reliable technique. However, using stool specimen for genotyping in our patients showed reduced sensitivity.

Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa

BMC Gastroenterology

Background: The global prevalence of H. pylori approaches 50%, with prevalence rates between 20 and 40% in developed countries and up to 90% in Africa and other developing nations of the world. Development of H. pylori-associated diseases is determined by a number of virulence factors. This study aimed at determining the prevalence of H. pylori infections and virulence genes (cagA, dupA, and vacA); the relationship between virulence factors and gastroduodenal diseases among patients. Methods: Gastric biopsies were obtained from patients and cultured, DNA was extracted from cultured isolates and biopsies for PCR assay after which samples were investigated using standard laboratory procedures. Data of associated risk factors were obtained with the aid of questionnaires. Results: Of the 444 participants, H. pylori was detected in 115 (25.9%) from culture analysis and 217 (48.9%) by direct PCR method. Ninety-eight (85.2%) of the culture-positive patients were also detected by PCR giving an overall prevalence of 52.7% (234/444). The highest number of H. pylori isolates 76.9% (180/234) was obtained from patients suffering from pangastritis. The CagA virulence gene was found in 62% (145/234), dupA in 53.4% (125/234) and vacA in 90.6% (212/234). VacA genotype s1 m1 was the most prevalent [56.4% (132)] followed by s2 m2 [11.5% (27)], s2 m1 [10.3% (24)] and [s1 m2 9.4% (22)]. There was a significant association observed in vacA s1 and peptic ulcer disease, as well as vacA s1/m2 and gastric erosion (P < 0.05). Conclusion: The study revealed a significant association between virulence genes and the development of certain forms of gastric infections while the variations in H. pylori detection and the associated risk factors investigated in the study were not significantly related.