title: Metronidazole and clarithromycin susceptibility and the subtypes of vacA of Helicobacter pylori isolates in Estonia.
abstract: The prevalence of metronidazole and clarithromycin resistance of Helicobacter pylori strains under different growth conditions (microaerophilic or anaerobic preincubation) was tested in 56 patients suffering from gastritis and peptic ulcer. vacA subtypes were detected in 46 H. pylori strains and were subsequently compared with the antibiotic resistance pattern. From 56 isolates, 26 proved resistant and 30 sensitive to metronidazole. The patients with peptic ulcer and gastritis were infected with both metronidazole-sensitive and metronidazole-resistant strains. In anaerobic preincubation all the strains were sensitive to metronidazole (MIC < 8 mg/l). All the strains were clarithromycin-sensitive (MIC < 2 mg/l). In the patients with gastritis and peptic ulcer s1 was the predominant vacA subtype. Comparison of vacA subtypes with the diagnoses revealed no correlation; different virulence factors such as vacA subtypes and antibiotic resistance to metronidazole in a microaerophilic milieu proved unrelated.
authors.affiliation: Department of Microbiology, University of Tartu, Estonia.
authors.forename: K
authors.initials: K
authors.lastname: Lõivukene
authors.forename: H
authors.initials: H
authors.lastname: Kolk
authors.forename: H I
authors.initials: HI
authors.lastname: Maaroos
authors.forename: P
authors.initials: P
authors.lastname: Kasenõmm
authors.forename: M
authors.initials: M
authors.lastname: Ustav
authors.forename: M
authors.initials: M
authors.lastname: Mikelsaar
mesh_terms: D000293:Adolescent; D000328:Adult; D000332:Aerobiosis; D000368:Aged; D000693:Anaerobiosis; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D017291:Clarithromycin / Q000494:pharmacology*; D005260:Female; D016480:Helicobacter pylori / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010437:Peptic Ulcer / Q000175:diagnosis / Q000382:microbiology; D016133:Polymerase Chain Reaction; D013276:Stomach Ulcer / Q000175:diagnosis / Q000382:microbiology; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; D008795:Metronidazole; D017291:Clarithromycin