virulence genes of minor ethnic groups in North Thailand.

BACKGROUND

There are few studies analyzed concurrently the prevalence and genotypes of infection with the ancestor origins from different ethnics, especially with including minority groups. We recruited a total of 289 patients in MaeSot, Thailand (154 Thai, 14 Thai-Chinese, 29 Karen and 92 Hmong ethnics). The virulence genes and genealogy of the strains were determined by PCR-based sequencing.

RESULTS

Based on culture and histology/immunohistochemistry, the prevalence of infection was 54.5% (158/289). Among 152 isolates cultured, the East-Asian-type was predominant genotype among strains from Hmong, Thai-Chinese and Thai (96.0% [48/50], 85.7% [6/7] and 62.7% [47/75], respectively), whilst majority of strains from Karen had Western-type (73.3% [11/15]). Patients infected with the East-Asian-type strains had significantly higher activity and intestinal metaplasia in the antrum and activity in the corpus than those with Western-type ( = 0.024, 0.006 and 0.005, respectively). The multilocus sequencing typing analysis discriminated that most strains from Hmong and Thai-Chinese belonged to hspEAsia (92.0 and 85.7%, respectively), whereas strains from Karen predominantly possessed hpAsia2 (86.7%) and strains from Thai were classified into hspEAsia (45.2%) and hpAsia2 (31.1%).

CONCLUSIONS

genotypes were relatively different among ethnic groups in Thailand and were associated with the source of ancestor even living in a small rural town. Caution and careful check-up are required especially on Hmong ethnic associated with high prevalence of virulence genotypes of .