There is continuing interest in identifying Helicobacter pylori virulence factors that might predict the risk for symptomatic clinical outcomes. It has been proposed thaticeA and cagA genes are such markers and can identify patients with peptic ulcers. We compared H. pylori isolates from four countries, looking at thecagA and vacA genotypes, iceAalleles, and presentation of the infection. We used PCR to examineiceA, vacA, and cagA status of 424H. pylori isolates obtained from patients with different clinical presentations (peptic ulcer, gastric cancer, and atrophic gastritis). The H. pylori isolates examined included 107 strains from Bogota, Colombia, 70 from Houston, Tex., 135 from Seoul, Korea, and 112 from Kyoto, Japan. The predominant genotype differed among countries: the cagA-positive iceA1 vacA s1c-m1 genotype was predominant in Japan and Korea, thecagA-positive iceA2 vacA s1b-m1 genotype was predominant in the United States, and the cagA-positiveiceA2 vacA s1a-m1 genotype was predominant in Colombia. There was no association between the iceA,vacA, or cagA status and clinical outcome in patients in the countries studied. iceA status shows considerable geographic differences, and neither iceA nor combinations of iceA, vacA, andcagA were helpful in predicting the clinical presentation of an H. pylori infection.
Geographic Differences in Gastric Cancer Incidence Can be Explained by Differences between Helicobacter pylori Strains
