title: Biotype and molecular fingerprints of metronidazole-resistant strains of Helicobacter pylori from antral gastric mucosa.
abstract: Biotypes, ribosomal RNA gene restriction patterns (ribopatterns), whole-cell protein patterns and plasmid profiles of paired Helicobacter pylori isolates from 17 patients were examined. Each pair comprised a pre- and a post-treatment isolate; nine of the 17 post-treatment isolates were obtained after treatment with tripotassium dicitrate bismuthate (De-Nol) and metronidazole. All strains of H. pylori had identical biotypes, but exhibited diversity between pairs in their molecular fingerprints. Each of the 17 strain pairs had unique ribopatterns; the pre- and post-treatment isolates in most pairs (16 of 17) were similar or identical, irrespective of metronidazole susceptibility. DNA subtype variants were detected in three patient sets. Although nine post-treatment isolates had acquired resistance to metronidazole, most (six of nine) resembled the pre-treatment isolates in their ribopattern, protein and plasmid profiles. No significant correlation was observed between metronidazole resistance and plasmid content in these H. pylori isolates. Emergence of post-treatment metronidazole-resistant isolates of H. pylori was associated only rarely with colonisation by a novel strain or acquisition of a plasmid and, in most patients, probably resulted from spontaneous emergence of resistance in the original infecting strain.
authors.affiliation: National Collection of Type Cultures, Central Public Health Laboratory, London.
authors.forename: R J
authors.initials: RJ
authors.lastname: Owen
authors.forename: G D
authors.initials: GD
authors.lastname: Bell
authors.forename: M
authors.initials: M
authors.lastname: Desai
authors.forename: M
authors.initials: M
authors.lastname: Moreno
authors.forename: P W
authors.initials: PW
authors.lastname: Gant
authors.forename: P H
authors.initials: PH
authors.lastname: Jones
authors.forename: D
authors.initials: D
authors.lastname: Linton
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis*; D004352:Drug Resistance, Microbial; D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology*; D010957:Plasmids; D011706:Pyloric Antrum; D012335:RNA, Ribosomal / Q000032:analysis; D015183:Restriction Mapping
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012335:RNA, Ribosomal; D008795:Metronidazole