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Genetic variability in parasites and host—parasite interactions

Published online by Cambridge University Press:  06 April 2009

R. C. A. Thompson and
A. J. Lymbery
R. C. A. Thompson
Affiliation:
Institute for Molecular Genetics and Animal Disease and WHO Collaborating Centre for the Molecular Epidemiology of Parasitic Infections, School of Veterinary Studies, Murdoch University, Murdoch, Western Australia, Australia6150
A. J. Lymbery
Affiliation:
Western Australian Department of Agriculture, Bunbury, Western Australia, Australia, 6230
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Summary

We have examined genetic variability in parasites in the context of ecological interactions with the host. Recent research on Echinococcus, Giardia and Cryptosporidium has been used to illustrate: (i) the problems that parasite variability and species recognition pose for understanding the complex and often controversial relationship between parasite and host occurrence; (ii) the need for accurate parasite characterization and the application of appropriate molecular techniques to studies on parasite transmission if fundamental questions about zoonotic relationships and risk factors are to be answered; (iii) our lack of understanding about within-host interactions between genetically heterogeneous parasites at the inter-and intraspecific levels, and the significance of such interactions with respect to evolutionary considerations and the clinical outcome of parasite infections. If advances in molecular biology and mathematical ecology are to be realized, we need to give serious consideration to the development of appropriate species concepts and in vivo systems for testing the predictions and assumptions of theoretical models.

Keywords

EchinococcusGiardiaCryptosporidiumgenetic variationmolecular characterizationhost occurrencespecies recognitionepidemiologyecological interactionsevolutionvirulence

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