Bottom-up regulation of malaria population dynamics in mice co-infected with lung-migratory nematodes

Griffiths, E., Fairlie-Clarke, K., Allen, J., Metcalf, C. J. and Graham, A. (2015) Bottom-up regulation of malaria population dynamics in mice co-infected with lung-migratory nematodes. Ecology Letters, 18(12), pp. 1387-1396. (doi: 10.1111/ele.12534) (PMID:26477454)

Abstract

When and how populations are regulated by bottom up vs. top down processes, and how those processes are affected by co-occurring species, are poorly characterised across much of ecology. We are especially interested in the community ecology of parasites that must share a host. Here, we quantify how resources and immunity affect parasite propagation in experiments in near-replicate ‘mesocosms’’ – i.e. mice infected with malaria (Plasmodium chabaudi) and nematodes (Nippostrongylus brasiliensis). Nematodes suppressed immune responses against malaria, and yet malaria populations were smaller in co-infected hosts. Further analyses of within-host epidemiology revealed that nematode co-infection altered malaria propagation by suppressing target cell availability. This is the first demonstration that bottom-up resource regulation may have earlier and stronger effects than top-down immune mechanisms on within-host community dynamics. Our findings demonstrate the potential power of experimental ecology to disentangle mechanisms of population regulation in complex communities.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fairlie-Clarke, Dr Karen
• Authors: Griffiths, E., Fairlie-Clarke, K., Allen, J., Metcalf, C. J., and Graham, A.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Ecology Letters
• Publisher: Blackwell
• ISSN: 1461-023X
• ISSN (Online): 1461-0248
• Copyright Holders: Copyright © 2015 Wiley
• First Published: First published in Ecology Letters 8(12):1387-1396
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.