Grant: Discovery Grants Program - Individual

With dwindling fisheries, aquaculture is taking an important role in the provision of fish and shellfish to global markets. However, growth of aquaculture is constrained by incidence of disease and high mortalities due to stressful environmental conditions such as crowding and pollution. The sheer nature of aquacultured animals requiring large aquatic holding facilities, makes it very cumbersome and highly expensive to have whole organisms as model systems to evaluate aspects of disease progression and/or evaluation of contaminating chemicals or of therapeutic compounds. This is especially true if the study of the pathogens of interest, are OBLIGATE intracellular microorganisms. As opposed to facultative intracellular pathogens or to extracellular pathogens that can be cultured and studied outside host cells, obligate intracellular pathogens are difficult to study, as they require host cells for growth and survival. The study of viruses, the ultimate obligate intracellular pathogen, was facilitated with the development and availability of long term culturable cells or cell lines. For many terrestrial organisms, including humans, cell cultures derived from the organisms of interest have been successfully used as models to study disease, drug effects, and the role of environmental variables in modulating their health. Thus the present proposal aims to study MICROSPORIDIA (a poorly characterized obligate intracellular fungal parasites), their mechanisms of pathogenicity, transmission, reproduction, host specificity, and interactions with environmental contaminants as well as to develop therapeutic and preventive measures to control these pathogens in aquacultured species using model fish cell cultures. The growth of aquaculture has led to increasing reports of emerging opportunistic microsporidial pathogens and outbreaks of microsporidiosis have become an important issue in the global as well as Canadian industry. Loma salmonae, Loma morhua, Glugea sp. are some of several fish-afflicting microsporidia that have been reported to occur in important Canadian fish species and will be researched in this proposal along with a model culturable microsporidia, Anncaliia algerae.