Cryptococcus neoformans MET5 Gene is not Essential for Virulence in the Silkworm Infection Model.

The involvement of the MET5 gene in virulence of Cryptococcus neoformans was examined using the silkworm Bombyx mori infection model. In the virulence assay, the met5Δ mutant showed virulence not significantly different from the wild-type strain, suggesting that the MET5 gene is not essential for full virulence of C. neoformans. The effect of silkworm hemolymph on the survival of the met5Δ mutant was also tested. The C. neoformans met5Δ strain incubated in the silkworm hemolymph for five days remained viable, suggesting that silkworm hemolymph supports survival of the met5Δ strain.