Palaeoparasitology and palaeogenetics: review and perspectives for the study of ancient human parasites

Abstract

While some species of parasites can be identified to species level from archaeological remains using microscopy (i.e. Enterobius vermicularis, Clonorchis sinensis), others can only be identified to family or genus level as different species produce eggs with similar morphology (i.e. Tænia sp. and Echinococcus sp.). Molecular and immunological approaches offer the possibility to provide more precise determination at the species level. They can also identify taxa when classic parasite markers such as eggs or cysts have been destroyed over time. However, biomolecules can be poorly preserved and modern reference DNA is available only for a limited number of species of parasites, leading to the conclusion that classic microscopic observation should be combined with molecular analyses. Here we present a review of the molecular approaches used over the past two decades to identify human pathogenic helminths (Ascaris sp., Trichuris sp., E. vermicularis, Fasciola sp. etc.) or protists (Giardia sp., Trypanosoma sp., Leishmania sp. etc.). We also discuss the prospects for studying the evolution of parasites with genetics and genomics.

Pre-Columbian zoonotic enteric parasites: An insight into Puerto Rican indigenous culture diets and life styles

“…These observations could have been due to degradation of the genetic material, primer-based variability if the eggs belonged to animal-borne parasites or even to larvae exiting the egg after defecation [31]. Although in our analysis we did not use conserved primers, arguably, the absence of parasite DNA accompanied with the positive identification of the eggs in our data could have resulted from degradation of genetic material or a reflection of the limited variance of helminth genomes in curated reference databases [1]. Network modeling is a flexible and useful manner to represent the subjects of a dataset and their relationships.…”

“…It is possible that the composition of protozoan cyst may undergo morphological changes as a result of the taphonomic processes that preserved these coprolites, and the small size (4-12 micrometers) makes them difficult to identify using light microscopy [30]. Previously protozoan cysts were successfully detected in ancient biological artifacts by immunofluorescence [1]. It is clear that different cysts may be refractory to degradation for different lengths of time and likely the resistance of the cyst walls determines the protection of the nucleic acids.…”

Metagenomics and microscope revealed T. trichiura and other intestinal parasites in a cesspit of an Italian nineteenth century aristocratic palace

“…Moreover, the opercula of Dicrocoelium eggs were open and did not preserve the DNA of the worm inside. However, differences between microscopic and genetic analyses have been already described and could be attributed to the different distribution of eggs in the samples analysed 5 .…”

“…Paleoparasitology, the study of ancient parasites recovered from archaeological sites, is a branch of paleopathology important to understand the health conditions and lifestyle of past populations 1 – 5 . Classical paleoparasitology consist on the rehydration and microscopic analysis of coprolites, latrine sediments, pelvic soil of skeletons or intestines of mummified bodies, followed by identification of recovered parasite eggs basing on morphometry and other characteristics (e.g.…”

Paleoparasitology in Russia, history and prospects

“…However, these findings are extremely rare as after the death of their host, temporary ectoparasites eagerly seek a replacement host (Huchet et al, 2013). Parasitic paleoprotistology is a promising, up-and-coming subject (Côtê and Le Bailly, 2017;Faulkner and Reinhard, 2014). The development of biological subdisciplines, elaboration of new molecular and genetic techniques has lately allowed to set ambitious research goals in this area of paleoparasitology (Côtê and Le Bailly, 2017).…”