Detection of cagA Gene in Helicobacter pylori Strains Isolatedfrom Gastrodudenal Diseases

Son, Hee Jung; Kim, Jae Jun; Lee, Hwa Young; Kim, Young Ho; Rhee, Poong Lyul; Koh, Kwang Cheol; Paik, Seung Woon; Rhee, Jong Chul; Choi, Kyoo Wan

Abstract

BACKGROUND/AIMS: It appeared to be geographic differences in the prevalence of cagA (cyto toxin-associated gene A) positive strains. We investigated the relationship between cagA bearing Hpylori strains and gastroduodenal diseases in Korea. Additionally we assessed the usefulness of reverse transcription-polymerase chain reaction (RT-PCR) for detecting cagA through comparison between RT-PCR of gastric biopsy specimens and PCR of bacterial isolates.
METHODS
Ninety-two patients were enrolled in this study. Antral biopsy specimens were taken for culture and RT-PCR
RESULTS
Culture or histology of antral biopsy specimens indicated that 82 (89.1%) of 92 patients were infected with H. pylori. H. pylori was isolated from 69 patients (25 patients with gastritis, 29 patients with peptic ulcer disease, 15 patients with gastric cancer). CagA was detected by PCR in 61 (88.4%) of the 69 patients. The 61 patients included 20 patients (80.0%) with gastritis, 26 patient (89.7%) with peptic ulcer disease and 15 patients (100%) with gastric cancer (p>0.05). Of 92 patients, RT-PCR of biopsy specimens were performed in 22 patients. Detection rate of cagA gene by RT-PCR and PCR of bacterial genomic DNA were correlated by 78.6% (11/14).
CONCLUSIONS
There was no relationship between cagA bearing H. pylori strains and gastroduodenal diseases Although cagA was rapidly detected by RT-PCR, it seemed to be less useful for diagnosing the presence of cagA gene than PCR of bacterial isolates.