Within-host and external environments differentially shape β-diversity across parasite life stages

Area of Science:

• Ecology
• Parasitology
• Community Ecology

Background:

• Community assembly drivers are key to understanding biological communities.
• Beta-diversity (β-diversity) concepts, applied to parasite communities, help assess infection risk across environmental gradients.
• Factors influencing β-diversity in immature parasite (larval) communities remain largely unknown, despite larvae being the infective stage.

Purpose of the Study:

• To investigate the links between β-diversity across different life stages of parasite communities.
• To identify within-host and extra-host drivers of adult and larval gastrointestinal nematode community similarity in African buffalo.
• To compare community-level processes in adult (within-host) and larval (extra-host) parasite stages.

Main Methods:

• Employed a cross-sectional approach using PERMANOVA to assess independent drivers of β-diversity in adult and larval nematode communities.
• Utilized a longitudinal approach with path analysis to link drivers of β-diversity between adult and larval parasite communities within the same host.
• Analyzed gastrointestinal nematodes infecting African buffalo in Kruger National Park, South Africa.

Main Results:

• Cross-sectional analysis indicated intrinsic, within-host traits significantly affected adult nematode β-diversity, while extrinsic, extra-host variables impacted larval nematode β-diversity.
• Longitudinal analysis provided evidence that within-host factors indirectly influenced larval communities through their effect on adult communities.
• Demonstrated distinct drivers for adult and larval parasite community similarity.

Conclusions:

• Provides crucial data for comparing community processes across different habitats (within-host vs. abiotic environment) for parasite life stages.
• Elucidates host infection risk via larval stages and drivers of adult parasite persistence.
• Offers insights valuable for predicting and preventing infectious diseases by understanding parasite community dynamics.