CagA genotype and drug resistance of Helicobacter pyloriHp

Objective To study the genotype of CagA and drug resistance to clarithromycin of Helicobacter pyloriHp (Hp).Methods Hp strains were isolated from 482 gastric mucosa biopsies of patients with peptic ulcer or gastritis in Youjiang Medical College for Nationalities.The amplification of CagA gene fragment was conducted with PCR.Resistance to clarithromycin of Hp was determined with E-test.Meanwhile,strains were genotyped with repetitive extragenic palindromicPCR(REP-PCR)and further clustered with NTsys₂ software.Results Totally 374 Hp strains were identified with 87 Hp strains of CagA gene positive and a positive rate of 23.3% (87/374).The 26 CagA gene positive and resistant to clarithromycin strains were divided into six genotype groups according to their 78% homology,with 3,3,8,4,6,2 strains in each Hp group,respectively.Conclusion The CagA gene positive and resistant to clarithromycin strains could be divided into six genotype groups and the resistance to clarithromycin of Hp is not associated with CagA gene.