Impact of host nutritional status on infection dynamics and parasite virulence in a bird-malaria system
Article first published online: 8 AUG 2013
© 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society
Journal of Animal Ecology
Volume 83, Issue 1, pages 256–265, January 2014
How to Cite
Cornet, S., Bichet, C., Larcombe, S., Faivre, B., Sorci, G. (2014), Impact of host nutritional status on infection dynamics and parasite virulence in a bird-malaria system. Journal of Animal Ecology, 83: 256–265. doi: 10.1111/1365-2656.12113
- Issue published online: 18 DEC 2013
- Article first published online: 8 AUG 2013
- Accepted manuscript online: 21 JUN 2013 10:15AM EST
- Manuscript Accepted: 15 JUN 2013
- Manuscript Received: 5 SEP 2012
- Université de Bourgogne, the Conseil Régional de Bourgogne and the CNRS
- Conseil Régional de Bourgogne (FABER. Grant Number: 06512AA07579-Faber2006-178
- ERC Starting Grant EVOLEPID. Grant Number: 243054
- Junior Research Fellowship from Jesus College, Oxford (UK) and the Tour du Valat, Camargue (France)
- avian malaria;
- environmental variation;
- host–parasite interaction;
- Plasmodium relictum ;
- Host resources can drive the optimal parasite exploitation strategy by offering a good or a poor environment to pathogens. Hosts living in resource-rich habitats might offer a favourable environment to developing parasites because they provide a wealth of resources. However, hosts living in resource-rich habitats might afford a higher investment into costly immune defences providing an effective barrier against infection. Understanding how parasites can adapt to hosts living in habitats of different quality is a major challenge in the light of the current human-driven environmental changes.
- We studied the role of nutritional resources as a source of phenotypic variation in host exploitation by the avian malaria parasite Plasmodium relictum. We investigated how the nutritional status of birds altered parasite within-host dynamics and virulence, and how the interaction between past and current environments experienced by the parasite accounts for the variation in the infection dynamics. Experimentally infected canaries were allocated to control or supplemented diets. Plasmodium parasites experiencing the two different environments were subsequently transmitted in a full-factorial design to new hosts reared under similar control or supplemented diets.
- Food supplementation was effective since supplemented hosts gained body mass during a 15-day period that preceded the infection. Host nutrition had strong effects on infection dynamics and parasite virulence. Overall, parasites were more successful in control nonsupplemented birds, reaching larger population sizes and producing more sexual (transmissible) stages. However, supplemented hosts paid a higher cost of infection, and when keeping parasitaemia constant, they had lower haematocrit than control hosts.
- Parasites grown on control hosts were better able to exploit the subsequent hosts since they reached higher parasitaemia than parasites originating from supplemented hosts. They were also more virulent since they induced higher mass and haematocrit loss.
- Our study highlights that parasite virulence can be shaped by the host nutritional status and that parasite can adapt to the environment provided by their hosts, possibly through genetic selection.