Effects of Anthropogenic Habitat Disturbance and Giardia duodenalis
Infection on a Sentinel Species' Gut Bacteria
Habitat disturbance, a common consequence of anthropogenic land use
practices, creates human-animal interfaces where humans, wildlife, and
domestic species can interact. These altered habitats can influence
host-microbe dynamics, leading to potential downstream effects on host
physiology and health. Here, we explored the effect of ecological
overlap with humans and domestic species and infection with the
protozoan parasite Giardia duodenalis on the bacteria of black and gold
howler monkeys (Alouatta caraya), a key sentinel species, in
northeastern Argentina. Fecal samples were screened for Giardia
duodenalis infection using a nested PCR reaction, and the gut bacterial
community was characterized using 16S rRNA gene amplicon sequencing.
Habitat type was correlated with variation in A. caraya gut bacterial
community composition but did not affect gut bacterial diversity.
Giardia presence did not have a universal effect on A. caraya gut
bacteria across habitats, perhaps due to the high infection prevalence
across all habitats. However, some bacterial taxa, such as
Actinobacteria, Bacteroidetes, Firmicutes, and Lachnospiraceae, were
found to vary with Giardia infection. While A. caraya’s behavioral
plasticity and dietary flexibility allow them to exploit a range of
habitat conditions, habitats are generally becoming more
anthropogenically disturbed, and thus, less hospitable. Alterations in
gut bacterial community dynamics are one possible indicator that A.
caraya may be reaching its physiological limits for plasticity since
changes in host-microbe relationships due to stressors from habitat
disturbance may lead to negative repercussions for host health. These
dynamics are likely relevant for understanding organism responses to
environmental change in other mammals.