Conservation and Diversity of the Helicobacter pylori Copper‐Transporting ATPase Gene (copA) Sequence Among Helicobacter Species and Campylobacter Species Detected by PCR and RFLP

Abstract

Helicobacter pylori is a causative pathogen of such human stomach diseases as chronic type B gastritis, ulcer, and possibly gastric carcinoma. As a cofactor in various redox enzymes and an essential trace metal required for the synthesis of metalloproteins, copper might play a role in the pathogenesis of H. pylori. A gene, copA, associated with copper transport, has been isolated from H. pylori UA802. In this study, conservation and diversity of this gene were analyzed among some Helicobacter and Campylobacter species.Twenty-one clinical isolates and strains of helicobacters and campylobacters were used in this study. Methods including polymerase chain reaction (PCR) amplification, restriction fragment-length polymorphisms (RFLPs), and hybridization were employed to carry out this work.The copA gene was highly conserved in all the H. pylori isolates tested (Helicobacter nemestrinae and Helicobacter felis but not in Helicobacter mustelae and the Campylobacter species), whereas the sequence downstream of the copA appears to diverge among H. pylori isolates. In addition, two restriction patterns of the PCR-amplified copA fragments from seven H. pylori isolates and H. nemestrinae were identified, and the RFLP of H. nemestrinae was identical to that of one of the H. pylori isolate group.The adenosine triposphatase-derived copper-transporting mechanism is employed by various H. pylori strains, H. nemestrinae, H. felis, and perhaps by other Helicobacter species. The nucleotide mutations have risen in the copA gene. It appears that there is a genetic relatedness of the copA gene to H. pylori and H. nemestrinae.