Use of polymerase chain reaction-amplified Helicobacter pylori urease structural genes for differentiation of isolates.

Helicobacter pylori has been demonstrated as an etiologic agent of human gastritis and peptic ulcer formation. However, there is no straightforward basis to distinguish different isolates. We used the polymerase chain reaction (PCR) to amplify the urease structural subunit genes, ureA and ureB, which, when digested with appropriate restriction endonucleases, allow the differentiation of patterns on agarose gels. PCR amplification was possible with DNA rapidly extracted from H. pylori by alkaline lysis and phenol-chloroform. The 2.4-kb PCR products amplified from 22 clinical isolates and subjected to HaeII restriction endonuclease digestion produced 10 distinct patterns on agarose gels, with two patterns being shared between five and six strains. PCR amplification of the urease genes may enable the differentiation of closely related H. pylori strains by restriction digest analysis of PCR-amplified ureA and ureB genes.