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Background. We compared results of genotyping of Helicobacter pylori cagA and vacA virulence genes in DNA from gastric biopsies, both paraffin‐embedded and frozen, and from stool samples, in order to evaluate the comparative sensitivity of the stool assay. Methods. Genomic DNA from paraffin‐embedded biopsies, unfixed frozen biopsies, and stool samples of the same 20 patients was amplified for the cagA gene, an empty site (which provides a positive signal for cagA negative strains) and for the s and m alleles of the vacA gene. Composite genotypes were determined by combining data from analysis of all three materials. Results. Analysis of none of the materials taken singly showed all of the genotypes revealed by all three materials taken together, probably because of sampling error. Analysis of paraffin biopsies revealed 83.5%, that of frozen biopsies revealed 74.7% and that of stools revealed 75.9% of the genotypes. There was no significant difference in the percentage of the H. pylori genotypes identified from the three materials. Analysis of combinations of frozen biopsies and stools revealed 89.9% of the composite genotypes, and that of paraffin biopsies and stools revealed 96.2% of the composite genotypes. Evidence of multiple genotypes was found in 10 of 20 (50%) of the cases. Conclusions. Any one of the investigated biological materials can be used for detection of cagA and vacA genes, but no single assay provided a complete genotype. The use of a combination of two materials may generate a more accurate representation of H. pylori genotypes in each individual. 相似文献
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Helicobacter pylori strain and the pattern of gastritis among first-degree relatives of patients with gastric carcinoma 总被引:1,自引:0,他引:1
Background. Relatives of gastric cancer patients have an increased risk of gastric cancer, possibly related to genetically‐related strains of Helicobacter pylori or a common environment. Methods. The pattern of gastritis and H. pylori from gastric cancer patients and their first‐degree relatives were compared using detailed DNA fingerprints and vacA, cagA, and iceA genotyping. Results. Sixteen index cases from Korea, the US, or Colombia and their 38 first‐degree relatives (brothers, sisters, sons and daughters) were studied. No definite, or consistent, relationship between the pattern of gastritis and the relatedness of the H. pylori strain was observed (i.e. relatives could have an identical or a totally different pattern of gastritis regardless if they were infected with identical or highly similar organisms). For example, three elderly siblings of an index case with atrophic pangastritis had identical H. pylori isolates and environments in childhood and yet two had antral predominant nonatrophic gastritis, which is typically associated with duodenal ulcer instead of gastric cancer. Conclusions. The results of this study are not consistent with the hypothesis that specific virulence factors or similar H. pylori strains correlate with a specific histologic pattern or outcome even among those sharing the same environment in childhood. 相似文献
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Age at acquisition of Helicobacter pylori infection: comparison of two areas with contrasting risk of gastric cancer 总被引:2,自引:0,他引:2
Background. Helicobacter pylori infection is usually acquired during childhood and is a known risk factor for the development of gastric malignancies in adulthood. It has been reported that early age at first infection may determine a neoplastic outcome in adults. The purpose of this study was to determine the prevalence of Helicobacter pylori infection in children residing in areas with high (Pasto) and low risk (Tumaco) of gastric cancer in Colombia to evaluate whether differences in the age of acquisition of H. pylori infection were present in the two populations. Materials and Methods. The study sample was based on a census taken in 1999. Using the 13C‐urea breath test, we compared the prevalence of H. pylori infection among children aged 1–6 years. Results. Among 345 children in Pasto, 206 (59.7%) were H. pylori‐positive, compared with 188 (58.6%) among 321 children in Tumaco. The two populations share a common pattern of very early age at infection and marked increase in prevalence during the first 4 years of life. No differences in any one year were observed when comparing the two groups. Conclusions. The prevalence of infection was similarly high and increased with age in both populations. In these populations the age of acquisition of H. pylori after 1 year of age does not appear to be a primary factor responsible for the differences in the rates of gastric cancer incidence in adults. Previous findings in adults showed lower prevalence of the most virulent genotypes in Tumaco compared to Pasto, and bacterial virulence may play a key role in determining cancer outcome. 相似文献
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Comparison of Gene Expression Between Pediatric and Adult Gastric Mucosa with Helicobacter pylori Infection 下载免费PDF全文
Naho Obayashi Yoshikazu Ohtsuka Kenji Hosoi Tamaki Ikuse Keisuke Jimbo Yo Aoyagi Tohru Fujii Takahiro Kudo Daisuke Asaoka Mariko Hojo Akihito Nagahara Sumio Watanabe Toshiaki Shimizu 《Helicobacter》2016,21(2):114-123
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Quantitative Detection and Genotyping of Helicobacter pylori from Stool using Droplet Digital PCR Reveals Variation in Bacterial Loads that Correlates with cagA Virulence Gene Carriage 下载免费PDF全文
Sarah Talarico Mahboobeh Safaeian Paula Gonzalez Allan Hildesheim Rolando Herrero Carolina Porras Bernal Cortes Ann Larson Ferric C. Fang Nina R. Salama 《Helicobacter》2016,21(4):325-333
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Polymorphisms in HLA‐DQ genes,together with age,sex, and Helicobacter pylori infection,as potential biomarkers for the early diagnosis of gastric cancer 下载免费PDF全文
Martha Pérez‐Rodríguez Oswaldo Partida‐Rodríguez Margarita Camorlinga‐Ponce Lourdes Flores‐Luna Eduardo Lazcano Alejandro Gómez Roberto Herrera‐Goepfert Rafael Medrano‐Guzmán Javier Torres 《Helicobacter》2017,22(1)