RESULTS: 96.6% (n=85) of H. pylori isolates were cagPAI-positive with 22.4% (19/85) having an intact cagPAI, whereas 77.6% (66/85) had a partial/rearranged cagPAI. The frequency of cag2 and cag14 were found to be significantly higher in H. pylori isolated from Malays, whereas cag4 was predominantly found in Chinese isolates. The cag24 was significantly found in higher proportions in Malay and Indian isolates than in Chinese isolates. The intactness of cagPAI region showed an association with histopathological scores of the gastric mucosa. Significant association was observed between H. pylori harbouring partial cagPAI with higher density of bacteria and neutrophil activity, whereas strains lacking cagPAI were associated with higher inflammatory score.
CONCLUSIONS: The genotypes of H. pylori strains with various cagPAI rearrangement associated with patients' ethnicities and histopathological scores might contribute to the pathogenesis of H. pylori infection in a multi-ethnic population.
METHODS: A prospective analysis of ninety nine H. pylori-positive patients who underwent endoscopy in our Endoscopy suite were included in this study. DNA was isolated from antral biopsy samples and the presence of cagA, iceA, and iceA2 genotypes were determined by polymerase chain reaction and a reverse hybridization technique. Screening for H. pylori infection was performed in all patients using the rapid urease test (CLO-Test).
RESULTS: From a total of 326 patients who underwent endoscopy for upper gastrointestinal symptoms, 99 patients were determined to be H. pylori-positive. Peptic ulceration was seen in 33 patients (33%). The main virulence strain observed in this cohort was the cagA gene isolated in 43 patients. cagA was associated with peptic ulcer pathology in 39.5% (17/43) and in 28% (16/56) of non-ulcer patients. IceA1 was present in 29 patients (29%) and iceA2 in 15 patients (15%). Ulcer pathology was seen in 39% (11/29) of patients with iceA1, while 31% (22/70) had normal findings. The corresponding values for iceA2 were 33% (5/15) and 33% (28/84), respectively.
CONCLUSION: Virulence factors were not common in our cohort. The incidence of factors cagA, iceA1 and iceA2 were very low although variations were noted in different ethnic groups.