Association between Helicobacter pylori Virulence Factors and Gastroduodenal Diseases in Okinawa, Japan

Matsunari, Osamu; Shiota, Seiji; Suzuki, Rumiko; Watada, Masahide; Kinjo, Nagisa; Murakami, Kazunari; Fujioka, Toshio; Kinjo, Fukunori; Yamaoka, Yoshio

doi:10.1128/jcm.01031-12

Cited by 56 publications

(56 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of the cagA and vacA s1a allele in 5/5 (100%) of the peptic ulcer disease cases is in agreement with results obtained in previous studies showing an association between these virulence factors and peptic ulcer development [5,6,12,35,[50][51][52]. Furthermore, as previously reported [14,20], the cagA gene was mostly associated with the vacA s1a allele (10/17; 58.8%), compared to vacA s1b and s2 alleles that were found in 2/17 (11.8%) and 4/17 (23.5%) of cagA-positive strains.…”

Section: Discussionsupporting

confidence: 91%

Prevalence of Helicobacter pylori cagA and vacA genes in Cypriot patients

Krashias

Bashiardes

Potamitou³

et al. 2013

J Infect Dev Ctries

View full text Add to dashboard Cite

Introduction: The prevalence of H. pylori varies with geographic locations. To date there are no epidemiological data on its prevalence in Cyprus; therefore, we determined the prevalence and molecular characteristics of H. pylori infection in Cypriot patients. Methodology: DNA extracted from 103 gastric biopsies was analyzed for the presence of H. pylori by PCR using primers for ureA. H. pyloripositive biopsies were characterized by PCR using specific primers for cagA and vacA genes. The presence of clarithromycin-associated resistant mutations such as A2143G, A2142G, A2142C in 23S rRNA gene of H. pylori-positive patients was determined using a real-time PCR allelic discrimination assay. Results: H. pylori was detected in 41 (39.8%) biopsies and, out of these, 17 (41.5%) tested positive for the cagA gene. The vacA alleles m1, m2, s1a, s1b, and s2 were detected in 7 (17.1%), 34 (82.9%), 12 (29.3%), 2 (4.9%), and 22 (53.7%) isolates, respectively. One (2.4%) biopsy was vacA s1a and s2-positive while one (2.4%) was positive for vacA s1a, s1b, and s2. Three (7.3%) biopsies were untypable for vacA s1, s1b, and s2. The majority (35; 85.4%) of strains were susceptible to clarithromycin while two (4.9%) had the A2143G mutation. Three (7.3%) had a mixture of an A2143G point mutant and susceptible strains while one (2.4%) had a mixture of an A2142G point mutant and susceptible strains. Conclusions: The distribution of the virulence factors cagA and vacA in the Cypriot strains resembled that of strains circulating in Middle Eastern countries geographically close to Cyprus.

show abstract

Section: Discussionsupporting

confidence: 91%

Prevalence of Helicobacter pylori cagA and vacA genes in Cypriot patients

Krashias

Bashiardes

Potamitou³

et al. 2013

J Infect Dev Ctries

View full text Add to dashboard Cite

show abstract

“…However, interestingly, we found a relatively low rate (70.3%) of East-Asian-type cagA strains in Okinawa compared with other parts of Japan. 15 Okinawa consists of small islands (2276 km 2 ) in southwestern Japan, with the lowest incidence of GC in Japan. Western-type cagA and cagA-negative strains were found to be 16.0% and 13.6%, respectively, of the strains isolated from Okinawa.…”

Section: Cytotoxin-associated Gene a (Caga)mentioning

confidence: 99%

The significance of virulence factors in Helicobacter pylori

Shiota

Suzuki

Yamaoka

2013

J of Digest Diseases

Self Cite

119

View full text Add to dashboard Cite

Helicobacter pylori (H. pylori) infection is linked to various gastroduodenal diseases; however, only a small fraction of these patients develop associated diseases. Despite the high prevalence of H. pylori infection in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than those in other countries. The incidence of gastric cancer tends to decrease from north to south in East Asia. Such geographic differences in the pathology can be explained, at least in part, by the presence of different types of H. pylori virulence factors in addition to the host and environmental factors. Virulence factors of H. pylori, such as cagA, vacA, dupA, iceA, oipA and babA, have been demonstrated to be predictors of severe clinical outcomes. Interestingly, meta-analysis showed that CagA seropositivity was associated with gastric cancer compared with gastritis even in East Asian countries where almost of the strains possessing cagA. Meta-analysis also confirmed the significance of vacA, dupA and iceA. However, there remains the possibility that additional important pathogenic genes can be existed because H. pylori consists of approximately 1 600 genes. Despite advances in our understanding of the development of H. pylori-related diseases, further work is required to clarify the roles of H. pylori virulence factors.

show abstract

“…Moreover, in transgenic mice expressing Western-type CagA (CagA-ABCCC), the frequency of malignant neoplasms was significantly lower than in mice expressing East Asian CagA [16]. In addition, molecular epidemiologic analyses from Asian populations reported that individuals infected with East Asian type cagA strains have an increased risk of peptic ulcer or gastric cancer when compared with those harboring Western-type cagA-H. pylori infection [17,18].…”

Section: Introductionmentioning

confidence: 97%