Helicobacter pylori cagA, iceA and vacA status in Taiwanese patients with peptic ulcer and gastritis.
BACKGROUND
Helicobacter pylori causes chronic gastritis, peptic ulcer, gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. Different genotypes of H. pylori are confirmed from diverse geographical areas. Its association with clinical diseases remains controversial. The aim of the present study was to investigate the H. pylori vacuolating cytotoxin (vacA) alleles, cytotoxin-associated gene (cagA) and iceA, in patients with peptic ulcer and gastritis.


METHODS
We enrolled patients with peptic ulcer and chronic gastritis. Biopsy specimens were obtained from the antrum and lower body of the stomach. DNA extraction and polymerase chain reaction (PCR) were used to detect the presence or absence of cagA and to assess the polymorphism of vacA and iceA.


RESULTS
A total of 133 patients (57 gastric ulcer, 52 duodenal ulcer, 24 chronic gastritis) had positive PCR results from biopsy specimens. Concerning genotypes, we found cagA (79% in the antrum, 92% in the body) and iceA1 (73% in the antrum, 82.8% in the body) strains in the majority of patients. The dominant vacA subtype was s1a (74.4% in the antrum, 75% in the body), followed by s1c (51.1% in the antrum, 60.5% in the body). In the middle region, the m2 strain dominated (49.6% in the antrum, 41.4% in the body), followed by m1T (19.5% in the antrum, 9.5% in the body). Mixed infection occurred in 89 patients (67%). There was no statistical difference in genotypes among the three groups.


CONCLUSIONS
In Taiwan, H. pylori with positive cagA and iceA1 was found in the majority of cases. H. pylori with vacA s1a strains was the most common vacA subtype, followed by s1c, while s1b was rare. In the middle region, the m2 subtype was predominant followed by m1T. There was no significant association between genotypes and clinical diseases.
Perng
Chin-Lin
CL
Division of Gastroenterology, Department of Medicine, VGH-TAIPEI, Taiwan.
Lin
Hwai-Jeng
HJ
Sun
I-Chen
IC
Tseng
Guan-Ying
GY
Facg
D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005756:Gastritis / Q000382:microbiology*; D005838:Genotype; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D013624:Taiwan
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C405087:iceA1 protein, Helicobacter pylori