Galleria mellonella as a model system to study Cryptococcus neoformans pathogenesis.

Published

Journal Article

Evaluation of Cryptococcus neoformans virulence in a number of nonmammalian hosts suggests that C. neoformans is a nonspecific pathogen. We used the killing of Galleria mellonella (the greater wax moth) caterpillar by C. neoformans to develop an invertebrate host model system that can be used to study cryptococcal virulence, host immune responses to infection, and the effects of antifungal compounds. All varieties of C. neoformans killed G. mellonella. After injection into the insect hemocoel, C. neoformans proliferated and, despite successful phagocytosis by host hemocytes, killed caterpillars both at 37 degrees C and 30 degrees C. The rate and extent of killing depended on the cryptococcal strain and the number of fungal cells injected. The sequenced C. neoformans clinical strain H99 was the most virulent of the strains tested and killed caterpillars with inocula as low as 20 CFU/caterpillar. Several C. neoformans genes previously shown to be involved in mammalian virulence (CAP59, GPA1, RAS1, and PKA1) also played a role in G. mellonella killing. Combination antifungal therapy (amphotericin B plus flucytosine) administered before or after inoculation was more effective than monotherapy in prolonging survival and in decreasing the tissue burden of cryptococci in the hemocoel. The G. mellonella-C. neoformans pathogenicity model may be a substitute for mammalian models of infection with C. neoformans and may facilitate the in vivo study of fungal virulence and efficacy of antifungal therapies.

Full Text

Duke Authors

Cited Authors

  • Mylonakis, E; Moreno, R; El Khoury, JB; Idnurm, A; Heitman, J; Calderwood, SB; Ausubel, FM; Diener, A

Published Date

  • July 2005

Published In

Volume / Issue

  • 73 / 7

Start / End Page

  • 3842 - 3850

PubMed ID

  • 15972469

Pubmed Central ID

  • 15972469

International Standard Serial Number (ISSN)

  • 0019-9567

Digital Object Identifier (DOI)

  • 10.1128/IAI.73.7.3842-3850.2005

Language

  • eng

Conference Location

  • United States