Determination of Helicobacter pylori Virulence Genes in Gastric Biopsies by PCR (original) (raw)
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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.
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.
AMB Express
Helicobacter pylori is one of the most common bacteria affecting human societies worldwide, and is mainly associated with gastrointestinal complications due to different virulence factors. This study aimed to investigate some virulence genes of H. pylori in gastric biopsies of patients with gastritis in Sari city, North of Iran. Informed consent forms were obtained from the studied patients, and those who needed endoscopy were included in the study. To evaluate the prevalence of cagA, iceA1, iceA2, vacA, dupA, and oipA genes, gastric biopsies with positive or negative rapid urease test were collected from 50 patients (25 in each group) with gastro-duodenal diseases. The bacterial DNAs were extracted by a specific kit, and the presence of the genes was analyzed by PCR using specific primers. Eighteen (72%) biopsies from 25 H. pylori-positive samples were cagA-positive, while 17 (68%) biopsies contained the vacA gene, and 11 (44%) samples had both vacA and cagA genes. However, 16 (64%...
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.
Diagnostic microbiology and infectious disease, 2008
Several tests/methods for the infection, detection, and genotyping of Helicobacter pylori have been developed in the past; all these differ in specificity and sensitivity and thereby could not be routinely used in clinical study especially in resource-poor developing countries. In the present study, a novel method based on multiplex polymerase chain reaction (PCR) assay was developed to detect H. pylori in patients suffering from gastrointestinal diseases. This method does not require steps of sonication, boiling, or centrifugation for obtaining DNA from biopsy samples, which are otherwise prerequisite in detecting H. pylori by PCR assay. Two hundred seventy-six patients were examined, of which 182 cases (excluding 36 patients having multiple H. pylori strain infection and 8 showing amplification of 16S rDNA only) were H. pylori positive. The dominant vacA genotype was s1 and m1 being present in 168 (92.3%) and 106 (58.2%) patients, respectively, followed by m2 (41.7%), and the lowest being s2 (7.7%). Detection of H. pylori by this method seems rapid, simpler, and suitable for both types 1 and 2 bacteria. Furthermore, genotyping of vacA and cagA genes could also be routinely performed in a large number of patients for diagnostic purposes.
Gene detection of Helicobacter-pylori by use real-time PCR in patients from Wasit province: Iraq
Journal of entomology and zoology studies, 2018
The present study was conducted to detect the Cytotoxin–associated gene A (CagA) specific for Helicobacter pylori by using PCR technique in gastric biopsy of patients in Wasit province at OGD (esophago gastroduodenal scope) Unit at Al-Zahraa Teaching Hospital in Wasit province upper endoscopy for the period from November 2016 to February 2017. Helicobacter pylori colonization with has been recognized as an important risk factor for a gastroduodenal disease accordingly, collected from 40 adult patients, 23 men and 17women, whose age range from 13 to 72 years suffer from dyspeptic symptoms. Referred to the OGD (esophago gastroduodenal scope) Unit at Al-Zahraa Teaching Hospital in Wasit province upper endoscopy for the period from November 2016 to February 2017. According to endoscopic diagnosis, the patients were grouped into gastritis, inflammation of the duodenum, stomach ulcers. Results of analysis of biopsy samples (in size 300mg) by polymerase chain reaction (RT PCR) as invasive ...
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.
Journal of Applied Microbiology, 2007
Aim: To evaluate and develop a multiplex polymerase chain reaction (PCR) assay for diagnosing and specific identification of virulent Helicobacter pylori strains and their main virulence genes cagA, cagE, cagT, vacA and hrgA.Methods and Results: Genomic DNA from 82 gastric tissues was screened. A master pool of all the ingredients of multiplex reaction was prepared for amplification. Amplicons were sequenced to confirm the amplification of each target genes. Multiplex PCR assay was able to detect all the five target genes in 81·7% and deletions in one or more loci among 18·3%. Genotype cagT +ve/hrgA +ve/cagA +ve/cagE +ve/vacAs1 +ve was more predominant in this study population (67·07%). hrgA, cagT, cagE and cagA genes were present in 100%, 92·7%, 85·4% and 81·7% of the subjects, respectively. The vacAs1 subtype had higher prevalence frequency in patients with overt gastrointestinal disease (78·57%) than with GERD (gastro-esophageal reflux disease) and NUD (non-ulcer dispepsia) (50%).Conclusions: The multiplex PCR assay developed herein was able to genotype H. pylori isolates based on the main virulence genes.Significance and Impact of the Study: The ability to identify H. pylori and the majority of their virulence gene markers by multiplex PCR assay represents a considerable advancement over other PCR-based methods for genotyping H. pylori from large population, and can be explored to gain insights at the genotypic variability exhibited by this pathogen.