pylori infection, the ASR of gastric cancer in the northern City of Hanoi is approximately 1.5 times higher than that in the southern City of Ho Chi Minh http://​www-dep.​iarc.​fr/​. pylori genotypes would differ between strains isolated from the two cities. Currently, however, there are few data about H. pylori genotypes isolated from Vietnam [26]. We therefore attempted to investigate several H. pylori genetic factors regarded as virulence or molecular epidemiologic markers in H. pylori isolates from Vietnam. Results Patients and H. pylori We recruited a total of 103 Vietnamese patients (47 males

and 56 females), aged 14 to 83 years (mean age, 45 years), of whom 54 were from Hanoi and 49 were from Ho Chi Minh. Twenty-five patients were judged to have peptic ulcer disease (16 from Hanoi and 9 from Ho Chi Minh) and 78 had chronic gastritis (38 from Hanoi find more and 40 from Ho Chi Minh). Classification of the cagA gene according to the pre-EPIYA region We analyzed the sequences of the cagA Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region

and upstream sequence of the EPIYA region of H. pylori isolated from Ho Chi Minh and Hanoi, located in the southern and northern parts of Vietnam, respectively. Except for five cases associated with cagA-negative strains, the EPIYA repeat region and pre-EPIYA region of the remaining 98 strains were successfully sequenced. The majority of Vietnamese strains (93%; 94/103) had an East Asian type EPIYA repeat with three EPIYA motifs (i.e., ABD type based on the previous classification [15, 27]), and only 4 strains (4%) had a Western type this website EPIYA repeat with three EPIYA motifs (i.e., ABC type) (Table 1). Table 1 Genotypes of cagA pre-EPIYA,cagA repeat, cag right-end

junction and vacA of Vietnamese H. pylori strains.     Total (n = 103) Ho Chi Minh (n = 49) Hanoi (n = 54) cagA pre-EPIYA Vietnamese pre-EPIYA type 80 (77%) 39 (80%) 41 (76%)   East Asian pre-EPIYA type 13 (13%) 4 (8%) 9 (17%)   Western pre-EPIYA type 5 (5%) 3 (6%) 2 (4%) cagA repeat East Asian type (ABD type) 94 (93%) 43 Protein kinase N1 (88%) 51 (94%)   Western type (ABC type) 4 (4%) 3 (6%) 1 (2%) cagA (-)   5 (5%) 3 (6%) 2 (4%) cag right-end I 9 (9%) 8 (16%) 1 (2%)   II 87 (84%) 37 (76%) 50 (93%)   III 4 (4%) 2 (4%) 2 (4%)   N.D. 3 (3%) 2 (4%) 1 (2%) vacA s* s1 103 (100%) 49 (100%) 54 (100%)   s2 1 (1%) 0 (0%) 1 (2%) vacA m† m1 44 (43%) 15 (31%) 29 (54%)   m2 54 (52%) 32 (65%) 22 (41%)   N.D. 5 (5%) 2 (4%) 3 (6%) N.D.: could not be determined. * Both s1 and s2 were detected in one case. † The prevalence of vacA m1 is significantly higher in Hanoi than in Ho Chi Minh, p < 0.05 Interestingly, about 300 bp upstream of the first EPIYA motif, we found that several strains carried a 39-bp or 18-bp deletion (Figure 1). All strains with the 39-bp and 18-bp deletion had an East Asian type EPIYA repeat and 4 of 5 (80%) strains without the deletion had a Western type EPIYA repeat.