Invertebrate Models for Studying Microbial Pathogenesis

Insects have an immune response structurally and functionally similar to the innate immune response of mammals and, since the innate immune response of mammals is a vital component in the overall immune response to pathogenic infections (Levy, 2001; Romani, 1999), many groups are now studying fungal virulence employing insects as model systems. Many different insect species have been employed to study microbe-host interactions and include Drosophila melanogaster, Galleria mellonella, Bombyx mori, and Manduca sexta. A wide range of microorganisms have been studied in insects including many bacterial (Dunphy et al., 1986; Morton et al., 1987; Bergin et al., 2005) and fungal pathogens (Mylonakis et al., 2005; Reeves et al., 2004; Cotter et al., 2000). Silva et al. (2002) employed M. sexta, to study the pathogenicity of the nematode symbiont, Photorhabdus luminescens, by investigating the effects of bacterial culture supernatants on haemocyte phagocytosis.

There have also been many reports of the efficacy of insects in studying the therapeutic effects of antibiotics (Hamamoto et al., 2004; Alippi et al., 2005) and the antimicrobial effects of various drugs (Lionakis et al., 2005; Lionakis & Kontoyiannis, 2005; Tickoo & Russell, 2002). Larvae of silkworms have been used to measure the efficacy of antibiotics in killing bacteria and a positive correlation with the results obtained with mice has been demonstrated (Hamamoto et al., 2004). The fruit fly, Drosophila melanogaster, has also been employed to investigate antifungal drugs and Aspergillus virulence. Lionakis and Kontoyiannis (2005) employed D. melanogaster as a fast, inexpensive high-throughput screening model for anti-Aspergillus compounds and in investigations of the role of Aspergillus virulence factors in pathogenesis. Although all Aspergillus virulence and therapeutic investigations cannot be performed in these models they do provide primary testing systems and may reduce the number of mammals being utilised.

Invertebrates such as Acanthamoeba castellanii, Caenorhabditis elegans, Dictyostelium discoidium, D. melanogaster, and G. mellonella have been employed to study the molecular mechanisms by which Cryptococcus neoformans interacts with the host (London et al., 2006) and revealed that several virulence-related genes previously known to be involved in C. neoformans mammalian infections also played a role in virulence in these invertebrates.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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