Evaluating the potency of zoliflodacin against Helicobacter pylori: In vitro activity and conserved GyrB target

Abstract

Background

The current standard treatment for Helicobacter pylori infection, which involves a combination of two broad-spectrum antibiotics, faces significant challenges due to its detrimental impact on the gut microbiota and the emergence of drug-resistant strains. This underscores the urgent requirement for the development of novel anti-H. pylori drugs. Zoliflodacin, a novel bacterial gyrase inhibitor, is currently undergoing global phase III clinical trials for treating uncomplicated Neisseria gonorrhoeae. However, there is no available data regarding its activity against H. pylori.

Materials and Methods

We evaluated the in vitro activity of zoliflodacin against H. pylori clinical isolates (n = 123) with diverse multidrug resistance. We performed DNA gyrase supercoiling and microscale thermophoresis assays to identify the target of zoliflodacin in H. pylori. We analyzed 2262 H. pylori whole genome sequences to identify Asp424Asn and Lys445Asn mutations in DNA gyrase subunit B (GyrB) that are associated with zoliflodacin resistance.

Results

Zoliflodacin exhibits potent activity against all tested isolates, with minimal inhibitory concentration (MIC) values ranging from 0.008 to 1 μg/mL (MIC₅₀: 0.125 μg/mL; MIC₉₀: 0.25 μg/mL). Importantly, there was no evidence of cross-resistance to any of the four first-line antibiotics commonly used against H. pylori. We identified GyrB as the primary target of zoliflodacin, with Asp424Asn or Lys445Asn substitutions conferring resistance. Screening of 2262 available H. pylori genomes for the two mutations revealed only one clinical isolate carrying Asp424Asn substitution.

Conclusion

These findings support the potential of zoliflodacin as a promising candidate for H. pylori treatment, warranting further development and evaluation.