High frequency of cytotoxin-associated gene A in Helicobacter pylori isolated from asymptomatic subjects and peptic ulcer patients in Taiwan

• Published in: Journal of clinical gastroenterology Vol. 27; no. 1; p. 54
• Main Authors: Shyu, R Y, Jiang, S Y, Lai, C H, Hsu, C T, Young, T H, Yeh, M Y
• Format: Journal Article
• Language: English
• Published: United States 01.07.1998
• Subjects: Aged; Antigens, Bacterial - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; DNA - analysis; Female; Gene Amplification; Helicobacter Infections - metabolism; Helicobacter Infections - physiopathology; Helicobacter pylori - genetics; Helicobacter pylori - immunology; Helicobacter pylori - pathogenicity; Humans; Male; Middle Aged; Peptic Ulcer - metabolism; Peptic Ulcer - microbiology; Peptic Ulcer - pathology; Polymerase Chain Reaction; Pyloric Antrum - metabolism; Pyloric Antrum - microbiology; Pyloric Antrum - pathology; Taiwan; Taiwan
• ISSN: 0192-0790; 1539-2031
• DOI: 10.1097/00004836-199807000-00011

Cytotoxin-associated gene A (CagA), expressed in about 60% of H. pylori isolates in Western countries, may play a role in the pathogenesis of peptic ulcer. In this study, we determined the prevalence and significance of the H. pylori cagA gene and protein expression in Taiwan. Genomic DNA from antrum biopsies and H. pylori isolates were analyzed for cagA using polymerase chain reaction, Southern hybridization, or colony hybridization. CagA seropositivity was analyzed using Helico blots. In addition, Western blotting was performed to detect the CagA protein. About 94% of antrum tissues from both asymptomatic subjects and duodenal ulcer patients and all 76 H. pylori isolates (21 asymptomatic subjects, 39 with duodenal ulcers, 13 with gastric ulcers, 2 with gastric cancers, and 1 with mucosa-associated lymphoid tissue [MALT] lymphoma) were positive for the cagA gene. Moreover 77 out of 78 H. pylori-positive serum and all 27 H. pylori lysates had anti-CagA antibodies or CagA protein, respectively. H. pylori isolated from patients with various upper gastrointestinal diseases in Taiwan contained the cagA gene and expressed CagA protein at high frequencies.