New Combinatorial Therapy Using Disulfiram or Aztreonam to Combat Helicobacter pylori

Helicobacter pylori (H. pylori) is a class II carcinogen and the emergence of antimicrobial resistance, especially clarithromycin-resistance, is a threat to public health. We aimed to find a novel therapy to combat H. pylori infection and identified aztreonam and disulfiram via a high-throughput screening of FDA-approved drugs. The monobactam aztreonam and the anti-alcohol dependence agent disulfiram were active against multidrug-resistant H. pylori, even at acidic pH, and no drug resistance emerged over 50 days of continuous exposure. Both agents inhibited clarithromycin-resistant H. pylori, downregulated H. pylori virulence factors, and reduced H. pylori load in gastric epithelial cells. Furthermore, they showed partial synergy with standard antibiotics (amoxicillin and clarithromycin) and proton pump inhibitors (omeprazole, pantoprazole, rabeprazole, and lansoprazole). We also designed and synthesized novel hybrid analogs of aztreonam and disulfiram, which exhibited 2-to-4-fold lower minimum inhibitory concentrations and reduced cytotoxicity compared to the parent molecules. In transcriptomic and metabolomic studies to explore the mechanism of action of aztreonam and disulfiram, host-pathogen interaction analysis using RNA-seq showed that both agents decreased H. pylori-induced upregulation of inflammatory and cancer-promoting genes in infected gastric epithelial cells. In vivo studies showed that aztreonam and disulfiram rescued H. pylori-infected Galleria mellonella (p<0.001) and, in a murine gastric infection model, orally administered single therapy with either agent reduced inflammation (p<0.0005) and eliminated H. pylori adherence to gastric mucosal and epithelial cells in a 14-day regimen. Similarly, triple therapy with aztreonam or disulfiram, a proton pump inhibitor (omeprazole), and a clinical antibiotic (amoxicillin) reduced inflammation (p<0.0005) after seven days of treatment. Fecal analysis using 16S rRNA gene sequencing revealed that the gut microbiome of the triple therapy-treated mouse group was similar to that of the control antibiotic-treated group. Our results show that the aztreonam and disulfiram can be repurposed to combat H. pylori infection but the oral formulation of aztreonam needs further study to be standardized.