Evaluation of Helicobacter pylori vacA genotype in Japanese patients with gastric cancer.

Shimoyama, Tadashi; Yoshimura, Teizo; Mikami, Taisei; Fukuda, Shinsaku; Je, Crabtree; Munakata, Akihiro

doi:10.1136/jcp.51.4.299

Cited by 30 publications

(16 citation statements)

References 11 publications

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“…There is global variation in the distribution of vacA alleles in different ethnic populations (27). The prevalence of s1c and s1a is high in strains from Asia; however, s1b is frequent in Southern Europe, South America, South Africa, and the United States (14,22,27,29).…”

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confidence: 99%

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Regional Variation amongvacAAlleles ofHelicobacter pyloriin China

Wang

Doorn²,

Robinson

et al. 2003

J Clin Microbiol

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Allelic variation among Helicobacter pylori vacA occurs in the signal and middle region of the gene. The aim of the study was to investigate alleleic variation of vacA among H. pylori strains from three regional areas of China and the relationship between vacA alleles and PUD. DNA extracted from 88 clinical isolates of H. pylori was analyzed by type-specific PCR and reverse hybridization line probe assay (LiPA) to determine the genotype of vacA and presence of cagA. In 87 isolates, all of the vacA alleles could be classified as either type s1c or type s1a, and all could be classified as m1, m2a, or m2b. One strain could not be typed. In all, 41% of patients were infected with multiple vacA genotypes, with the highest level being observed in Shanghai (63%). In strains from Beijing, s1a was dominant; by contrast, s1c was dominant in Guangxi and Shanghai. The prevalence of m2b strains in Shanghai (63%) was significantly higher than that in Beijing (83%) or Guangxi (0%). Thirty of the 87 patients had peptic ulcers. However, there was no association between vacA genotype and PUD. This study demonstrates that there is significant geographic diversity of genotype of vacA within China. The absence of vacA s2 genotypes precluded analysis of an association of vacA s genotypes and clinical disease.

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confidence: 99%

“…However in Japan, South Korea, and China, where s1 alleles predominate, vacA genotypes have not been associated with more severe clinical outcome (20,22,29). Global variation in the distribution of vacA alleles may explain diverse reports linking vacA genotype to clinical disease from different geographic areas.…”

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confidence: 99%

Regional Variation amongvacAAlleles ofHelicobacter pyloriin China

Wang

Doorn²,

Robinson

et al. 2003

J Clin Microbiol

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“…The association of the speci®c vacA genotypes with cytotoxin activity Med Microbiol Immunol (1999) 188: 131±138 and peptic ulcers was ®rst described for H. pylori isolates from the United States [2,5] and con®rmed in several studies [17,23,27,30,34]. Of note, this association was not found in H. pylori strains from Japanese patients [19,21,29,39], or other countries [8,38]. One United States study also failed to demonstrate an association [15].…”

Section: Introductionmentioning

confidence: 91%

“…However, the number of H. pylori strains that remain untypeable is considerable [8,15,17,19,21,23,25,27,29,30,34,37,39]. The originally described primer set [2] requires separate PCR runs to type m1 and m2.…”

Section: Introductionmentioning

confidence: 99%

One-step polymerase chain reaction-based typing of Helicobacter pylori vacA gene: association with gastric histopathology

Han

Schneider

Loos

et al. 1999

Medical Microbiology and Immunology

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Heterogeneity of the Helicobacter pylori vacA gene may be associated with bacterial virulence and presentation. In this study, the possible correlation between vacA genotypes and gastric histopathology was investigated. Using a modified one-step polymerase chain reaction (PCR)-based method, 122 of 131 H. pylori isolates obtained from 63 of 67 patients from Germany were classified into distinct vacA genotypes according to their signal sequence (s1 or s2) and their midregion alleles (m1 or m2). A possible subtype of ml, now alluded to as m3, was identified in one-third of the isolates. Signal sequence s1 was significantly associated with higher H. pylori density but not with gastric inflammation parameters as compared with s2. Compared with m2, ml initially appeared to correlate with higher mononuclear cell scores in corpus, although not with H. pylori density. Upon differentiation between ml and m3, however, only the latter was associated with the high cell scores. Moreover, m3 also correlated with a higher antral H. pylori density. Positive cagA status correlated significantly with vacA signal sequence s1, and higher gastric mononuclear cell scores and corpus neutrophil score. H. pylori density was always associated with enhanced gastric neutrophil and corpus mononuclear cell scores. These data indicate a significant association of specific vacA genotypes with enhanced bacterial density and gastric inflammation. PCR-based identification of the respective alleles can now easily be performed in the diagnostic laboratory using a one-step PCR assay.

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“…It may be concluded that the s1 allele is linked to peptic ulcer development, and hence to greater virulence. However, despite this association between s1/m1 vacA genotype and presence of peptic ulcer, together with an increased infiltration by neutrophils and lymphocytes in vivo, greater in ulcer patients versus gastritis patients, this association is not so obvious in Asian countries, where both conditions exhibit a similar incidence regarding the s1/m1 genotype (41,42).…”

Section: Vacuolizing Cytotoxin (Vaca)mentioning

confidence: 99%