Assessment of East Asian-type cagA-positive Helicobacter pylori using stool specimens from asymptomatic healthy Japanese individuals.
Recent investigations have suggested that CagA, a virulence factor of Helicobacter pylori and known to have multiple genotypes, plays a critical role in the development of stomach cancer. However, the prevalence of cagA-positive H. pylori strains and the cagA genotypes have not been well studied in healthy individuals because of the difficulty in collecting gastric specimens. In the present study, we assessed the prevalence of infection with H. pylori, particularly the strains with the East Asian cagA genotype (which is more potent in causing gastric diseases), among healthy asymptomatic Japanese individuals by a noninvasive method using stool specimens. The H. pylori antigen was detected in 40.3 % of healthy asymptomatic adult individuals (n=186) enrolled in the study. For the detection and genotyping of the cagA gene, DNA was extracted from the stool specimens of these individuals and analysed by PCR. We detected the East Asian cagA genotype in the DNA samples of a significantly high number (63.1 %) of healthy asymptomatic Japanese individuals. These results indicate that a significant number of asymptomatic healthy Japanese individuals were infected with highly virulent H. pylori.
Hirai
Itaru
I
Department of Bioinformatics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
Sasaki
Tadahiro
T
Department of Bioinformatics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
Kimoto
Ai
A
Department of Bioinformatics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
Fujimoto
Saori
S
Department of Bioinformatics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
Moriyama
Toshiki
T
Health Care Center, Osaka University, Osaka 560-0043, Japan.
Yamamoto
Yoshimasa
Y
Department of Bioinformatics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
D000328:Adult; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005243:Feces / Q000382:microbiology*; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014774:Virulence
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; C080866:cagA protein, Helicobacter pylori