Helicobacter pylori cagA,iceAandvacAgenotypes in patients with gastric cancer in Taiwan

Lin, Hwai Jeng; Perng, Cherng-Kang; Lo, Wen-Ching; Wu, Chew-Wun; Tseng, Guan-Ying; Li, Anna Fen–Yau; Sun, I‐Chen; Ou, Yueh‐Hsing

doi:10.3748/wjg.v10.i17.2493

Cited by 27 publications

(14 citation statements)

References 47 publications

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“…The s1b types are rare in other regions and less virulent than other s1 subtypes (2,3,10,19,20,22,23). Furthermore, although the s1c allele has been stated to be more common in Asian strains and it may be associated with gastric cancers that are prevalent in that region, other studies have, in contrast, indicated that cancer development cannot be explained by s1c alleles alone (4,12,(18)(19)(20)23). Thus, the relationship between the genotypes of causative strains and clinical outcome should be considered in different geographic regions in order to make a true estimation of prognosis.…”

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confidence: 70%

Prevalence and Genotypes of Helicobacter pylori in Gastric Biopsy Specimens from Patients with Gastroduodenal Pathologies in the Cukurova Region of Turkey

et al. 2009

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The effects of Helicobacter pylori genotypes on clinical prognosis in the Cukurova region of Turkey were investigated by PCR. The prevalence of type I strains carrying the s1c allele, unlike in neighboring regions and countries, was found to be significantly higher in patients with gastritis and/or gastric ulcers (P ‫؍‬ 0.001), and that of type I strains carrying the s1a allele was found to be significantly higher in patients with duodenal ulcers (P < 0.001). The cagA gene was strongly associated with the more virulent vacA genotypes (P < 0.001).

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confidence: 70%

Prevalence and Genotypes of Helicobacter pylori in Gastric Biopsy Specimens from Patients with Gastroduodenal Pathologies in the Cukurova Region of Turkey

et al. 2009

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“…In both studied groups, we found H. pylori strains that were untypeable for the signal-sequence and mid-region alleles due to significant variation in the vacA gene [8], [24]. We consistently found that the cagA - and vacA -allele diversity was greater in the tumor, suggesting that H. pylori can remain in the tumor without environmental stress.…”

Section: Discussionmentioning

confidence: 95%

High Diversity of vacA and cagA Helicobacter pylori Genotypes in Patients with and without Gastric Cancer

et al. 2008

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Background Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer.Methodology/Principal FindingsThree gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008), and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003). A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036). A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003). Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins.Conclusion/SignificanceHigh H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work.

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“…pylori strains. However, most of the vacA s regions were of the s1a subtype, which is less frequently found in patients with gastric cancer than in those with peptic ulcers and chronic gastritis [ 47 ] or is present only in dyspeptic patients [ 48 ]. In addition, the predominant m region subtype was m1c, which is specific to South Asian countries with a low ASR of gastric cancer.…”

Section: Discussionmentioning

confidence: 99%

Two populations of less-virulent Helicobacter pylori genotypes in Bangladesh

et al. 2017

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Bangladesh has a population with a low gastric cancer risk but high prevalence of Helicobacter pylori infection. Several studies have examined virulence genes in H. pylori from Bangladesh. We analyzed cagA and vacA subtypes and their association with severe histology phenotypes, and analyzed population types among Bangladeshi strains. We included patients who underwent endoscopy in Dhaka. Sequences of virulence genes and seven housekeeping genes were obtained by next generation sequencing and confirmed by Sanger sequencing. We isolated 56 H. pylori strains from 133 patients, of which 73.2% carried cagA, and all were considered Western-type. Patients infected with cagA-positive strains had more severe histological scores than patients infected with cagA-negative strains. Among vacA s1 and m1 genotypes, the s1a (97.8%, 43/44) and m1c (28/30, 93.3%) genotypes were predominant. All strains containing s1 and m1 (30/56, 53.6%) also had i1, d1, and c1. In contrast, all strains containing the less-virulent genotypes s2 and m2 (12/56, 21.4%) also possessed i2, d2, and c2. Multivariate analysis indicated that subjects infected with vacA m1-genotype strains only had a significantly higher risk of antrum atrophy than patients infected with m2-genotype strains. Of the two main H. pylori populations in this study, hpAsia2 strains were associated with higher activity and inflammation in the antrum compared to hpEurope strains; however, only vacA s1m1i1d1c1 strains, independent of population type, were significantly associated with inflammation in the antrum, unlike the s2m2i2d2c2 genotype. In conclusion, Bangladeshi strains were divided into two main populations of different genotypes. The low incidence of gastric cancer in Bangladesh might be attributable to the high proportion of less-virulent genotypes, which may be a better predictor of gastric cancer risk than the ancestral origin of the H. pylori strains. Finally, the vacA m region may be a better virulence marker than other regions.

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Helicobacter pylori cagA,iceAandvacAgenotypes in patients with gastric cancer in Taiwan

Cited by 27 publications

References 47 publications

Prevalence and Genotypes of Helicobacter pylori in Gastric Biopsy Specimens from Patients with Gastroduodenal Pathologies in the Cukurova Region of Turkey

Prevalence and Genotypes of Helicobacter pylori in Gastric Biopsy Specimens from Patients with Gastroduodenal Pathologies in the Cukurova Region of Turkey

High Diversity of vacA and cagA Helicobacter pylori Genotypes in Patients with and without Gastric Cancer

Two populations of less-virulent Helicobacter pylori genotypes in Bangladesh

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