Helicobacter pylori Antimicrobial Susceptibility Testing-Guided Salvage Therapy in the USA: A Real Life Experience.

Background: The current practice guidelines recommend that Helicobacter pylori (H. pylori) culture and antimicrobial susceptibility testing (AST) be considered after patients failed the second course of H. pylori eradication therapy.

Aims: Here we report the real life experience of following this recommendation in the USA.

Methods: We established an in-house H. pylori culture protocol for AST and identified retrospectively patients who previously failed ≥ 2 courses of anti-H. pylori therapy and underwent esophagogastroduodenoscopy with AST at University of Michigan from 2010 to 2017. We determined the rate of H. pylori antibiotic resistance, the success rates of AST-guided tailored therapy, and the risk factors associated with treatment failure.

Results: Forty-seven patients were identified and 34 (72.3%) had successful cultures and AST. The most common antibiotic resistance was to metronidazole (79.4%), followed by clarithromycin (70.6%) and ciprofloxacin (42.9%). None of the patients were resistant to amoxicillin or tetracycline. The overall success rate of AST-guided tailored therapy was low (44.4%, 12/27). In patients infected with metronidazole-resistant H. pylori, bismuth quadruple therapy appears to be superior compared to non-bismuth quadruple therapy (6/8 or 75.0% vs. 3/14 or 21.4%, P = 0.03). High body mass index was significantly associated with tailored therapy failure (OR 1.24, 95% CI 1.00-1.54, P = 0.049).

Conclusions: The success rate of AST-guided salvage therapy in the USA is low particularly in those with high BMI. Bismuth-based therapy appears to be better than non-bismuth-based regimens.