Galleria mellonella larvae as a model for Helicobacter pylori biofilm formation under antibiotic stress.

Helicobacter pylori is a common Gram-negative bacterium that inhabits the human stomach and causes a variety of gastric pathologies. One of the growing concerns is its dynamic spread of antibiotic resistance, a process in which biofilm formation is involved. Therefore, it is necessary to find an appropriate, high-throughput research model for the in vivo biofilm development by H. pylori. The aim of the current research report was to determine the usefulness of G. mellonella larvae in assessing the survival of a multidrug-resistant, strong biofilm producing H. pylori strain during its exposure to stress caused by clarithromycin. Using infection models lasting for 3 or 6 days, we confirmed the ability of the tested H. pylori strain to survive in the larvae. We noticed that exposure to clarithromycin significantly reduced the number of cultured bacteria relative to the control, although we did not observe any differences in the number of bacteria using time-lapse, live analysis of fluorescently stained larval hemolymph samples. In conclusion, we confirmed that the examined H. pylori strain can produce biofilm in G. mellonella larvae organism and is able to survive exposure to minimal inhibitory concentrations of clarithromycin (established in vitro) in in vivo conditions. Further refinement of methodologies for monitoring the viability of clinical H. pylori strains in the greater wax moth larvae will enhance the accuracy and reliability of this promising research model.