Small worms big discoveries: Galleria mellonella as a model for Campylobacter jejuni infection

Galleria mellonella larva have served as a simple, cost-effective model for studying innate immunity and Campylobacter jejuni infection. The model commonly employs an acute, high-dose septic infection via hemocoel injection, with observable endpoints of death and melanization. Studies using G. mellonella have provided insights into C. jejuni virulence factors, including the capsule, transcriptional regulators, outer membrane vesicles, and a T6SS. It has revealed signals for virulence, such as pancreatic amylase and growth temperature, and also allowed for comparisons between C. jejuni strains and across multiple species in the genus. Limitations include the use of high bacterial doses that may obscure the role of specific virulence factors, lack of accounting for larval size variations, and unclear connection to the human anaerobic, microbially-rich gut environment. Future development of this model could allow oral infections for exploring pathogen-microbiome interactions and further assessing mechanisms of this important pathogen.