Quasispecies of Antibacterial Heteroresistant <i>Helicobacter pylori</i>

Original Article

The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2004;4(1):7-14.
Published online June 30, 2004.

Quasispecies of Antibacterial Heteroresistant Helicobacter pylori

상이내성을 지닌 Helicobacter pylori 균주의 다종

이선영·이용찬*·표재희^†·권동현^‡·이종철·김재준

성균관대학교 의과대학 내과학교실, 연세대학교 의과대학 내과학교실*, 소화기병 연구소^†, 미국 Baylor 의과대학 내과^‡

Abstract

Background/Aims: Antibiotic heteroresistant Helicobacter pylori can be present simultaneously in the same host due to diverse genomic variation. The aim of this study was to evaluate the H. pylori strains resulting in heteroresistant antibacterial phenotypes, and to evaluate the roles of rdxA and frxA genes in metronidazole resistance. Methods: We compared the genotypes of 21 antibiotic heteroresistant H. pylori isolates from the antrum and corpus by random arbitrarily primed PCR and flagella gene PCR-based restriction fragment length polymorphism. The sequence variation of rdxA and frxA gene was analyzed in isolates showing heterotype metronidazole resistance. Results: DNA fingerprinting patterns of the paired- isolates from the antrum and corpus revealed that 14 pairs (66.7%) were identical whereas 1 pair (3.8%) was different. The remaining 6 pairs (28.6%) of isolates showed slightly different fingerprinting patterns while maintaining major bands. Among the 7 metronidazole-resistant strains, no sequence variation of the rdxA or frxA genes was noticed in 2 pairs (28.6%). Conclusions: Our finding suggests that quasispecies may play an important role in modulating the antibiotic heteroresistant H. pylori in vivo. In addition, the mutations in the rdxA and/or frxA genes cannot be used in predicting metronidazole resistance because some are irrelevant to these mutations. (Korean J Helicobacter Upper Gastrointest Res 2004;4:7-14)

Key Words: Helicobacter pylori, Drug resistance, Quasispecies, Metronidazole, Gene mutation