ABSTRACT
Variation amongst strains of Helicobacter pylori and Helicobacter mustelae was examined by DNA restriction endonuclease digestion and rRNA gene patterns generated using a non-radioactive probe. Chromosomal DNA was extracted from 30 cultures of H. pylori from human, Rhesus monkey and pig gastric mucosa, and from three H. mustelae isolates from ferret gastric mucosa. DNA fingerprinting with Hae III and Hind III showed H. mustelae was relatively homogeneous but revealed genomic heterogeneity within H. pylori with at least 18 different DNA patterns identifiable amongst the 30 isolates. Five sets of strains other than duplicates with matching DNA fingerprints were identified within H. pylori. The Peruvian isolates were the largest identical set and comprised eight isolates from four different patients with five consecutive isolates from one patient. The Rhesus monkey strains were a relatively homogeneous set as were several Australian human isolates. The study demonstrates that rRNA gene restriction patterns provide a simple but highly discriminatory electrophoretic fingerprint for H. pylori with potential for use as a novel epidemiological marker in addition to total DNA digest analysis.