Analysis of 3'-end variable region of the cagA gene in Helicobacter pylori isolated from Iranian population.
OBJECTIVE
The 3' region of the cagA gene, the most well-known virulence factor of Helicobacter pylori, contains Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs. Four segments flanking the EPIYA motifs, EPIYA-A, -B, -C, or -D, were reported to play important roles in H. pylori-related gastroduodenal pathogenesis. The aim was to determine the roles of EPIYA segments in gastroduodenal pathogenesis in an Iranian population.


METHODS
A total of 92 cagA-positive Iranian strains isolated from dyspepsia patients with non-ulcer dyspepsia (n = 77), peptic ulcer (n = 11) and gastric cancer (n = 4) were studied. The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing.


RESULTS
A total of 86 (93.5%) strains had three copies of EPIYA (ABC type), three (3.3%) had four copies (ABCC type) and three (3.3%) had two copies (AB type). The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences (EPIYATIDFDEANQAG) in Iranian strains. When the prevalence of strains with multiple EPIYA-C segments in Iran was compared with previously published data, it was much lower than that in Colombia and Italy, but was higher than that of Iraq, and the patterns were parallel to the incidence of gastric cancer in these countries.


CONCLUSIONS
The structure of the 3' region of the cagA gene in Iranian strains was Western type. Although we could not find differences between EPIYA types and clinical outcomes, low prevalence of strains with multiple EPIYA-C segments might be reasons for low incidence of gastric cancer in Iran.
Research Center of Gastroenterology and Liver Diseases, Shahid Beheshti University, MC, Tehran, Iran.
Leila
L
Shokrzadeh
Kaveh
K
Baghaei
Yoshio
Y
Yamaoka
Hossein
H
Dabiri
Fereshteh
F
Jafari
Navid
N
Sahebekhtiari
Ali
A
Tahami
Mitsushige
M
Sugimoto
Homayon
H
Zojaji
Mohammad Reza
MR
Zali
D000328:Adult; D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics*; D044466:Asian People; D001426:Bacterial Proteins / Q000235:genetics*; D004415:Dyspepsia / Q000208:ethnology / Q000382:microbiology*; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications / Q000208:ethnology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010641:Phenotype; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D013274:Stomach Neoplasms / Q000208:ethnology / Q000382:microbiology*; D013276:Stomach Ulcer / Q000208:ethnology / Q000382:microbiology*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori