Journal: bioRxiv

Article Title: Galleria mellonella as a novel invertebrate model for studying Ehrlichia ruminantium pathogenesis and host-pathogen interactions

doi: 10.64898/2026.04.29.721731

Figure Lengend Snippet: Long-term persistence of viable E. ruminantium within G. mellonella hemocytes. (A) Fluorescence microscopy of hemolymph collected 6 days post-infection, showing sustained intracellular bacterial presence within hemocytes. Nuclei are stained with Hoechst (blue) and bacteria with rhodamine (red). Scale bar, 30 μm. (B) Stereomicroscopy demonstrating whole-larva bacterial fluorescence persistence at 8 days post-infection. Scale bar, 5 mm. (C) Viability confirmation through re-infection assay. Hemolymph from infected G. mellonella was inoculated onto bovine aortic endothelial cell (BAEC) monolayers. At 4 days post-inoculation, characteristic morulae formation, lysis areas, and fluorescent bacteria within BAEC confirm maintenance of bacterial viability and infectivity throughout the larval infection period. Scale bar, 100 μm. N, nuclei; DPI, days post-infection.

Article Snippet: Samples were stained with 100 μL of 10 μg/mL Hoechst 33342 (Sigma-Aldrich) for 15-30 minutes at room temperature before microscopic examination using a fluorescent cell imager (ZOE, BioRad).

Techniques: Fluorescence, Microscopy, Infection, Staining, Bacteria, Lysis