title: Metronidazole resistance: a predictor of failure of Helicobacter pylori eradication by triple therapy.
abstract: Triple therapy (bismuth and two antibiotics) will eradicate Helicobacter pylori infection in 70-90% of subjects. Treatment failure has been attributed to patient compliance and antimicrobial drug resistance. The aim of this study was to examine factors influencing the eradication of H. pylori following triple therapy. Thirty seven subjects with H. pylori cultured from antral biopsies were treated with colloidal bismuth subcitrate (120 mg qid for 2 weeks), metronidazole (400 mg tid for 1 week) and amoxycillin (500 mg tid for 1 week). Pretreatment isolates of H. pylori were tested for metronidazole susceptibility by agar dilution according to the National Committee for Clinical Laboratory Standards guidelines. Factors including age, sex, clinical diagnosis and metronidazole resistance were evaluated in relation to H. pylori. The overall metronidazole resistance was 32%. Metronidazole resistant strains were more frequent in females, with a resistance rate of 54%. Helicobacter pylori eradication occurred in 68% of patients with a metronidazole susceptible stain and only 17% of patients with a metronidazole resistant strain (P < 0.03). Helicobacter pylori eradication is dependent upon susceptibility to metronidazole. This data would support the role for routine metronidazole susceptibility testing using appropriate standardized methods when triple therapy is to be considered.
authors: Department of Microbiology, Monash Medical Centre, Melbourne, Australia.
authors: P D
authors: PD
authors: Midolo
authors: J R
authors: JR
authors: Lambert
authors: J
authors: J
authors: Turnidge
mesh_terms: D000658:Amoxicillin / Q000008:administration & dosage; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D000897:Anti-Ulcer Agents / Q000008:administration & dosage*; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination / Q000008:administration & dosage*; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D010406:Penicillins / Q000008:administration & dosage; D011237:Predictive Value of Tests; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D009942:Organometallic Compounds; D010406:Penicillins; D008795:Metronidazole; D000658:Amoxicillin; C002791:bismuth tripotassium dicitrate