Bridging the gap in AMR research: validation of a standardized Galleria mellonella model to evaluate Clostridioides difficile pathogenesis and treatment efficacy
Year: 2026
Type: article
Abstract: Background Clostridioides difficile infection (CDI) is a significant global health burden. Galleria mellonella offers an ethical, cost-effective invertebrate alternative to mammalian pre-clinical models. This study evaluated the feasibility of using Galleria mellonella to study CDI pathogenesis and treatment. Methods We optimized larval storage, temperature, and inoculum size. The model was validated by assessing survival following infection with diverse C. difficile ribotypes (RT) and vancomycin treatment. Bacterial burden was quantified via qPCR, and survival was analyzed using Kaplan-Meier curves. Results An inoculum of 1 × 10 7 CFU/mL in fresh larvae (<7 days since receipt) at 37 °C proved optimal. Fresh larvae exhibited significantly higher survival compared to older larvae (P = 0.003). Infection with toxigenic strains resulted in significantly lower survival (35%) compared to uninfected controls (90%; P < 0.001), with virulence varying significantly among RTs. Vancomycin treatment improved survival to 90% in a dose-dependent manner compared to untreated controls (P < 0.001), with a corresponding reduction in bacterial burden confirmed by qPCR. Conclusion We conclude that this optimized oral G. mellonella model provides a robust and ethically sound high-throughput platform for screening novel anti- C. difficile compounds and for comparative virulence studies of diverse ribotypes, effectively bridging in vitro assays and mammalian studies for future drug development.
Source: Frontiers in Pharmacology
Authors: Faris S. Alnezary, Masaad Saeed Almutairi
Institutions: Taibah University, Qassim University
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
Funder: Qassim University
OpenAlex ID: W7154121452