Getting deep in the gut: novel explorations of parasite gut communities

Background/Question/Methods

In the last decades, parasite biology was conducted using a one host-one parasite framework, but evidence recently suggests that a more complex approach is needed. In natural systems, individuals are often co-infected by many species of parasites. At Mountain Lake Biological Station (MLBS), evidence suggests that wild Peromyscus populations can carry up to 10 different species of parasite, and most individuals are co-infected with 2 or more parasites. It has been theorized that endo-parasite communities may function in a similar manner as typical ecological communities. However, consequences of alterations to the parasite network are unknown in many cases. To test this idea, classic ecological concepts were applied to a natural host-parasite system consisting of two host species (Peromyscus maniculatus and Peromyscus leucopus) by disturbing the parasite communities through nematode removal. 

Results/Conclusions

No statistically significant differences in the parasite communities were detected pre- and post-treatment. However, interesting trends were reported in Ivermectin treated mice that were infected with nematodes that were limited  to just one site of the digestive tract, while the control group had a random distribution of worms throughout the gut. The remaining community may seem affected post-treatment showing a decrease in intestinal parasite burden and species richness of ecto-parasites, possibly because of a strong immune response that stimulated changes in the normal intestinal architecture. We may need longer trapping sessions and more than one grid, to have a good sample size in order to get more conclusive results and evidence the consequences of the alteration of the parasite network community.