PCR-RFLP product of patient sample from 1 to 6 PCR analysis amplified DNA fragment 820 base pair from biopsy with restriction enzymes HhaI (H), MboI (M), Hind III (Hn) of patients recurenceH. pyloriafter eradication treatment M: DNA maker A: DNA primary infection strains B: DNA Recurence strain after eradication UreC: Product PCR of UreC gene Mbo I: Amplification of UreC DNA segment cut with Mbo I Hind III: Amplification of UreC DNA segment cut withHind III Hha I: Amplification of UreC DNA segment cut withHha I 16.