Galleria melonella as an experimental in vivo host model for the fish-pathogenic oomycete Saprolegnia parasitica

Abstract

Oomycetes are eukaryotic pathogens infecting animals and plants. Amongst them Saprolegnia parasitica is a fish pathogenic oomycete causing devastating losses in the aquaculture industry. To secure fish supply, new drugs are in high demand and since fish experiments are time consuming, expensive and involve animal welfare issues the search for adequate model systems is essential. Galleria mellonella serves as a heterologous host model for bacterial and fungal infections. This study extends the use of G. mellonella for studying infections with oomycetes. Saprolegniales are highly pathogenic to the insects while in contrast, the plant pathogen Phytophthora infestans showed no pathogenicity. Melanisation of hyphae below the cuticle allowed direct macroscopic monitoring of disease progression. However, the melanin response is not systemic as for other pathogens but instead is very local. The mortality of the larvae is dose-dependent and can be induced by cysts or regenerating protoplasts as an alternative source of inoculation.

Cell entry of a host-targeting protein of oomycetes requires gp96

“…As a proof of concept, we have tested if molecular tweezers were able to prevent an infection of Galleria mellonella larvae by S. parasitica 24 . For this, protoplasts were either pre-incubated with molecular tweezers for 1 h or co-injected with molecular tweezers into larvae (Fig.…”

“…An infection assay with G. mellonella was used to determine the effect of the molecular tweezers on the virulence of S. parasitica 24 . Five larvae per group were injected with 1000, 500, 250 or 0 protoplast as indicated.…”

The insect, Galleria mellonella, is a compatible model for evaluating the toxicology of okadaic acid

“…Larvae of the greater wax moth, Galleria mellonella , have been developed to interrogate the pathogenicity of microbes (Lim et al 2018 ), efficacy of novel biopharmaceuticals, and toxicity of diverse chemicals (Allegra et al 2018 ; Maguire et al 2016 ; Wuensch et al 2018 ). In addition to their ease-of-use, low maintenance costs, and lack of legislative/ethical restrictions, the recent publication of the G .…”

Galleria mellonella experimental model for bat fungal pathogen Pseudogymnoascus destructans and human fungal pathogen Pseudogymnoascus pannorum

“…Many earlier publications have described the wax moth model as a preferred in vivo system for the study of human, insect, and fish pathogenic fungi [23–27]. Our findings are novel as we took advantage of the G. mellonella ability to survive in a wide range of temperature to conduct the experiments at low temperature.…”