A rapid identification scheme for Helicobacter pylori and other species of Helicobacter based on 23S rRNA gene polymorphisms

Restriction fragment length polymorphism (RFLP) analysis of a similar to 2.6-kbp PCR-amplified DNA fragment of the 23S (large subunit) ribosomal RNA gene was performed on 92 strains selected to represent 12 species of Helicobacter as well as ''Flexispira rappini'' and Wolinella succinogenes. The amplicon was digested with four restriction endonucleases (HaeIII, HpaII, CfoI and Hinfl). The PCR-RFLP profiles obtained from the type strains were used to build an identification scheme which was then assessed using available field strains. The scheme is based on the use of HaeIII as first choice enzyme, combined with HpaII for confirmation purposes, and in some particular cases with CfoI and Hinfl to increase discrimination. The proposed scheme is useful for differentiation of Helicobacter species from each other and has the potential of being expanded to include the increasing number of new Helicobacter species being described. Therefore, it can be a valuable tool for routine identification when used in combination with relevant phenotypic tests.