Fingerprinting of Nigerian Helicobacter pylori isolates by plasmid profile and PCR

Plasmid profiling and digestion of amplified PCR product of ureA genes were used to determine genomic variation in 56 strains of Helicobacter pylori isolated from patients with peptic ulcers and subjects with gastritis recruited in Lagos and Ife, Nigeria. Twenty-five (45%) of the strains were found to harbour plasmids ranging in size from 0.9 kb to > 10 kb. The plasmid profile was able to detect differences between the strains, and also to distinguish between different strains isolated from the same patient. The expected amplified ureA gene PCR product was detected in all strains and digestion with the restriction enzyme DdeI did not produce discrimination amongst the strains, however, digestion with MluI produced little discrimination amongst strains. In conclusion, plasmid profiling produced better discrimination amongst H. pylori strains than ureA PCR gene profiling.