title: Clarithromycin and amoxicillin susceptibility of Helicobacter pylori strains isolated from adult patients with gastric or duodenal ulcer in Italy.
abstract: Helicobacter pylori strains, isolated from 100 gastric biopsies from 49 previously untreated adult patients with endoscopy and histology-confirmed gastric or duodenal ulcer, were tested for in vitro antimicrobial susceptibility. Strains were isolated from biopsies of 75.5% (37 of 49) patients before therapy and of 13.5% after therapy. Clarithromycin and amoxicillin susceptibility testing was performed on pretreatment and posttreatment strains by using the agar disk diffusion method and E-test, a quantitative technique for the minimal inhibitory concentration (MIC) determination. All strains (n = 53) were susceptible to amoxicillin by the two methods. Three strains of 34 (8.8%) patients were resistant to clarithromycin: two by both methods and one by E-test (MIC > 2 microg/ml). E-test, although more expensive than the disk diffusion method, is easy to perform and is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory.
authors.affiliation: Infectious Diseases Unit, University of Turin, Corso Svizzera 164, 10131 Turin, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Franzin
authors.forename: M
authors.initials: M
authors.lastname: Pennazio
authors.forename: D
authors.initials: D
authors.lastname: Cabodi
authors.forename: F
authors.initials: F
authors.lastname: Paolo Rossini
authors.forename: P
authors.initials: P
authors.lastname: Gioannini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004352:Drug Resistance, Microbial; D004381:Duodenal Ulcer / Q000382:microbiology*; D005260:Female; D016480:Helicobacter pylori / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D006801:Humans; D007558:Italy; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010406:Penicillins / Q000494:pharmacology*; D013276:Stomach Ulcer / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins; D000658:Amoxicillin; D017291:Clarithromycin