TY - JOUR
T1 - The dilution effect behind the scenes
T2 - Testing the underlying assumptions of its mechanisms through quantifying the long-term dynamics and effects of a pathogen in multiple host species
AU - Garrido, Mario
AU - Halle, Snir
AU - Flatau, Ron
AU - Cohen, Carmit
AU - Navarro-Castilla, Álvaro
AU - Barja, Isabel
AU - Hawlena, Hadas
N1 - Funding Information: This work was supported by the Israel Science Foundation (no. 1391/15 to HH) and by the United States-Israel Binational Science Foundation (no. 2012063 to H.H. (PI), Clay, Fuqua, and Dong). Publisher Copyright: © 2021 The Author(s).
PY - 2021/6/9
Y1 - 2021/6/9
N2 - Disentangling the mechanisms that mediate the relationships between species diversity and disease risk has both theoretical and applied implications. We employed a model system of rodents and their Mycoplasma pathogens, in which an extreme negative diversity-disease relationship was demonstrated, to test the assumptions underlying three mechanisms that may explain this field pattern. Through quantifying the long-term dynamics and effects of the pathogen in its three host species, we estimated the between-host differences in pathogen spreading and transmission potentials, and host recovery potential and vulnerability to infection. The results suggest that one of the hosts is a pathogen amplifier and the other two hosts function as diluters. Considering the similarity in infection success and intensity among hosts, and the failure to detect any pathogen-induced damage, we could not validate the assumption underlying the hypotheses that diluters reduce the overall transmission or increase the mortality of infected hosts in the system. Instead, the results demonstrate that diluters clear the infection faster than amplifiers, supporting the possibility that the addition of diluters to the community may reduce the overall number of infected hosts through this mechanism. This study highlights the contribution of experimental studies that simultaneously explore different aspects of host-pathogen interactions in multiple hosts, in diversity-disease research.
AB - Disentangling the mechanisms that mediate the relationships between species diversity and disease risk has both theoretical and applied implications. We employed a model system of rodents and their Mycoplasma pathogens, in which an extreme negative diversity-disease relationship was demonstrated, to test the assumptions underlying three mechanisms that may explain this field pattern. Through quantifying the long-term dynamics and effects of the pathogen in its three host species, we estimated the between-host differences in pathogen spreading and transmission potentials, and host recovery potential and vulnerability to infection. The results suggest that one of the hosts is a pathogen amplifier and the other two hosts function as diluters. Considering the similarity in infection success and intensity among hosts, and the failure to detect any pathogen-induced damage, we could not validate the assumption underlying the hypotheses that diluters reduce the overall transmission or increase the mortality of infected hosts in the system. Instead, the results demonstrate that diluters clear the infection faster than amplifiers, supporting the possibility that the addition of diluters to the community may reduce the overall number of infected hosts through this mechanism. This study highlights the contribution of experimental studies that simultaneously explore different aspects of host-pathogen interactions in multiple hosts, in diversity-disease research.
KW - dilution effect
KW - diversity-disease relationship
KW - infected host mortality
KW - multi-host communities
KW - recovery augmentation
KW - transmission reduction
UR - http://www.scopus.com/inward/record.url?scp=85107967865&partnerID=8YFLogxK
U2 - https://doi.org/10.1098/rspb.2021.0773
DO - https://doi.org/10.1098/rspb.2021.0773
M3 - Article
C2 - 34102894
SN - 0962-8452
VL - 288
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
IS - 1952
M1 - 20210773
ER -