Narayanan, G.L.; Letley, D.P.; Aviles, F.; Bebb, J.R.; Hardie, K.R.; Atherton, J.C.
April 2003
Gut;Apr2003 Supplement 1, Vol. 52, pA53
Academic Journal
Introduction: Levels of vacuolating cytotoxin gene (vacA) transcription vary among laboratory strains of H pylori. We aimed to study the importance of vacA transcriptional differences among wild type strains and explore whether specific genetic determinants within vacA explained these differences. Methods: H pylori single colonies were isolated from gastric biopsy specimens from 8 patients and their vacA type determined by allele-specific PCR. Total RNA was prepared for each isolate and for the control strains 60190 (Tox[sup +]; vacA s1/m1) and Tx30a (Tox; s2/m2). Level of vacA transcription was determined by densitometric analysis of RNA dot blots. Level of VacA protein production was determined by densitometric analysis of immunoblots of 24 hour broth culture supernatants. For each isolate, nucleotide sequences were determined for the region between vacA and its 5' gene, cysS (the cysS-vacA intergenic region) and For 122 nucleotides of the 5' end of vacA. Finally, the vacuolating activity of each strain was determined by cell culture assay. Results: vacA transcription varied 6 fold among the clinical isolates. VacA RNA levels correlated closely with protein levels suggesting that variation in vacA production resulted mainly from variation in transcription. Level of vacA transcription was not related to vacA genotype (genotypes of wild type isolates were: 2 s1/m1; 4 s1/m2; 1 s2/m2; 1 s2/m1) nor was it associated with disease state or specific gastric histological features. Analysis of the cysS-vacA intergenic region revealed 70% identity across all 10 strains (including control strains 60190 and Tx30a). The -10 and -35 promoter regions were well conserved. Identity within the vacA 5' untranslated region was 77%. Despite high variation within the cysSvacA intergenic region, none of the genetic differences were associated with vacA transcription level. A potential stem-loop structure at the +4 site was conserved between all strains. Conclusion: Level of vacA...


Related Articles

  • Involvement of Ras and AP-1 in Helicobacter pylori-Induced Expression of COX-2 and iNOS in Gastric Epithelial AGS Cells. Soon Ok Cho; Joo Weon Lim; Kyung Hwan Kim; Hyeyoung Kim // Digestive Diseases & Sciences;Apr2010, Vol. 55 Issue 4, p988 

    Helicobacter pylori ( H. pylori) is an important risk factor for chronic gastritis, peptic ulcer, and gastric cancer. The genetic differences of H. pylori isolates play a role in the clinical outcome of the infection. Inflammatory genes including cyclooxygenase-2 (COX-2) and inducible nitric...

  • Genetic Variants Associated With Susceptibility to Helicobacter pylori. Wurfel, Mark M.; Hawn, Thomas R. // JAMA: Journal of the American Medical Association;9/4/2013, Vol. 310 Issue 9, p976 

    A letter to the editor is presented in response to the article "Identification of genetic loci associated with Helicobacter pylori serologic status," by J. Mayerle and colleagues.

  • Helicobacter pylori Infection: Genetic and Environmental Influences. Malaty, Hoda M.; Engstrand, Lars; Pedersen, Nancy L. // Annals of Internal Medicine;6/15/94, Vol. 120 Issue 12, p982 

    Presents information on a study which investigated the importance of genetic effects for acquiring Helicobacter pylori infection. Methodology; Results and discussion; Conclusions.

  • The complete genome sequence of the gastric pathogen Helicobacter pylori. Tomb, Jean-F.; White, Owen // Nature;8/7/1997, Vol. 388 Issue 6642, p539 

    Discusses the complete genome sequence of the gastric pathogen Helicobacter pylori. What sequence analysis indicates; The possibility that the mucosal pathogen uses recombination and slipped-strand mispairing within repeats as mechanisms for antigenic variation and adaptive evolution; What its...

  • Decreased miR-204 in H. pylori-Associated Gastric Cancer Promotes Cancer Cell Proliferation and Invasion by Targeting SOX4. Zhou, Xiaoying; Li, Lin; Su, Jing; Zhang, Guoxin // PLoS ONE;Jul2014, Vol. 9 Issue 7, p1 

    Background: The molecular mechanism between Helicobacter pylori (H. pylori) infection and gastric cancer remained largely unknown. In this study, we determined the role of miRNA in H. pylori induced gastric cancer. Methods and Results: We found that miR-204 was decreased in H. pylori positive...

  • The combined presence of H pylori infection and gastro-oesophageal reflux disease leads to an up-regulation of CDX2 gene expression in antrum and cardia. J Bornschein // Journal of Clinical Pathology;Mar2009, Vol. 62 Issue 3, p254 

    BACKGROUND: CDX2 is an epithelial transcription factor that regulates intestinal differentiation and is involved in the development of intestinal metaplasia (IM). AIM: To analyse the expression of CDX2 in the gastric mucosa in various locations and its relationship to Helicobacter pylori...

  • Interleukin-1B signalling leads to increased survival of gastric carcinoma cells through a CREB-C/EBPβ-associated mechanism. Resende, Carlos; Regalo, Gonçalo; Durães, Cecília; Pinto, Marta; Wen, Xiaogang; Figueiredo, Ceu; Carneiro, Fátima; Machado, José // Gastric Cancer;Jan2016, Vol. 19 Issue 1, p74 

    Background: Polymorphisms in inflammation-related genes have been associated with a risk of gastric carcinoma (GC). However, the biological mechanisms underlying these associations are still elusive. Our objective was to determine whether chronic inflammation-associated IL1Î’ signalling, as...

  • A bug with excess gastric avidity. Doolittle, Russell F. // Nature;8/7/1997, Vol. 388 Issue 6642, p515 

    Announces that the genome of the bacterium, Helicobacter pylori, that is responsible for peptic ulcers, has been completely sequenced. Features revealed; The letters written by Australian physician, Robin Warren, and his colleague Barry Marshall, a biochemist in 1983 on the subject; Results...

  • Helicobacter pylori vacA and cagA Genotypes in Mexican Adults and Children. Gonzalez-Valencia, G.; Atherton, J. C.; Munoz, O.; Dehesa, M.; Madrazo-de la Garza, A.; Torres, J. // Journal of Infectious Diseases;11/1/2000, Vol. 182 Issue 5, p1450 

    Assesses Helicobacter pylori vacA and cagA genotypes in adults and children in Mexico. Obtaining of H. pylori culture from gastric biopsy specimens; Incidence of different vacA genotypes; Association of mixed infection with ulcer disease; Difference of strain populations affecting adults and...


Read the Article


Sign out of this library

Other Topics