Françoise Bouchet

Parasite remains in archaeological sites

Organic remains can be found in many different environments. They are the most significant source for paleoparasitological studies as well as for other paleoecological reconstruction. Preserved paleoparasitological remains are found from the driest to the moistest conditions. They help us to understand past and present diseases and therefore contribute to understanding the evolution of present human sociality, biology, and behavior. In this paper, the scope of the surviving evidence will be briefy surveyed, and the great variety of ways it has been preserved in different environments will be discussed. This is done to develop to the most appropriated techniques to recover remaining parasites. Different techniques applied to the study of paleoparasitological remains, preserved in different environments, are presented. The most common materials used to analyze prehistoric human groups are reviewed, and their potential for reconstructing ancient environment and disease are emphasized. This paper also urges increased cooperation among archaeologists, paleontologists, and paleoparasitologists.

The state of the art of paleoparasitological research in the old world

Paleoparasitology in the Old World has mainly concerned the study of latrine sediments and coprolites collected from mummified bodies or archaeological strata, mostly preserved by natural conditions. Human parasites recovered include cestodes, trematodes, and nematodes. The well preserved conditions of helminth eggs allowed paleoepidemiological approaches taking into account the number of eggs found by archaeological stratum. Tentatively, sanitation conditions were assessed for each archaeological period.

Ancient DNA from Ascaris : extraction amplification and sequences from eggs collected in coprolites

On the Middle-Age site of Namur (Belgium) the analysis of coprolites revealed the presence of many well-preserved Ascaris eggs. Following rehydratation of the coprolite samples, 104 eggs were collected and extracted with an ultrasonication and phenol-chloroform based method. Three overlapping fragments of the 18S rRNA gene and one fragment of the cytochrome b gene have been reproducibly amplified, cloned and sequenced. The analysis of these sequences confirms the identification of the eggs as coming from Ascaris. Our study reveals that coprolites can be an interesting source of parasites that can be readily identified using molecular approaches. The study of ancient DNA from helminth parasites is of interest as it may answer long-standing questions in the history of infectious diseases and gives a possibility to compare these ancient sequences with those of modern populations.

Parasitism, the diversity of life, and paleoparasitology

The parasite-host-environment system is dynamic, with several points of equilibrium. This makes it difficult to trace the thresholds between benefit and damage, and therefore, the definitions of commensalism, mutualism, and symbiosis become worthless. Therefore, the same concept of parasitism may encompass commensalism, mutualism, and symbiosis. Parasitism is essential for life. Life emerged as a consequence of parasitism at the molecular level, and intracellular parasitism created evolutive events that allowed species to diversify. An ecological and evolutive approach to the study of parasitism is presented here. Studies of the origin and evolution of parasitism have new perspectives with the development of molecular paleoparasitology, by which ancient parasite and host genomes can be recovered from disappeared populations. Molecular paleoparasitology points to host-parasite co-evolutive mechanisms of evolution traceable through genome retrospective studies.

Identification of parasitoses in a child burial from Adak Island (Central Aleutian Islands, Alaska)

Bothriocephalid (Diphyllobothrium pacificum) and Ascarid (Ascaris lumbricoides) eggs have been identified in a sample taken in the abdominal cavity of a child skeleton found in Zeto Point (ADK-011), an archaeological site on Adak Island in the Central Aleutian Islands (Alaska).

First paleoparasitological analysis of a midden in the Aleutian Islands (Alaska): results and limits.

Excavations on Buldir Island, Aleutian Islands, Alaska, have revealed the remains of several features dated between the 13th and 17th centuries A.D. Soil from an open-air workshop, represented by 2 excavated pits, and a structure built of whale bones were sampled for evidence of parasites and microfloristic remains. Two groups of helminth eggs (Diphyllobothrium and Ankylostomidae) were identified in samples from the open-air pits; microfloristical remains were found in all samples. This is the first paleoparasitological analysis conducted on an Aleutian midden.

Amoebiasis distribution in the past: first steps using an immunoassay technique

The identification of parasites in ancient human faeces is compromised by differential preservation of identifiable parasite structures. However, protein molecules can survive the damage of the environment and can be detected even after centuries. In this paper it is shown that is possible to detect copro-antigen of Entamoeba histolytica in historic and prehistoric human faecal remains, using a commercially available enzyme immunoassay (ELISA) kit. The kit uses monoclonal antibody-peroxidase conjugate specific for E. histolytica adhesin. A total of 90 specimens of desiccated faeces found in mummies and ancient organic sediment from South America, North America, Africa, and Europe were examined. The ELISA detected 20 positive samples, dated to about 5300 years before present to the 19th Century ad. The positive samples are from archaeological sites in Argentina, USA, France, Belgium, and Switzerland. The detection of protozoan antigen using immunoassays is a reliable tool for the studies of intestinal parasites in the past.

Detection of Giardia duodenalis antigen in coprolites using a commercially available enzyme-linked immunosorbent assay

The objective of this experiment was to assess the utility of a commercially available enzyme-linked immunosorbent assay (ELISA) kit for diagnosis of giardiasis in archaeological human remains. The kit, a monoclonal antibody assay, is used to detect the presence of Giardia-specific antigen 65 (GSA65) in human faeces. We utilized the assay in ancient faecal material. The material included desiccated faeces found in mummies or in archaeological sites, and sediments from latrines. A total of 83 specimens, previously examined microscopically for parasites, were examined. The ELISA detected 3 positive samples, dated to about 1200 AD, 1600 AD and 1700 AD. The ELISA was superior to direct observation. It was possible to identify G. duodenalis cysts by direct microscopy in only one of these samples. The results did not show cross-reactivity between this protozoan and helminths. The use of ELISA to detect G. duodenalis coproantigen could help the diagnosis of giardiasis in ancient human remains.

Evolution of ascariasis in humans and pigs: a multi-disciplinary approach

The nematode parasite Ascaris lumbricoides infects the digestive tracts of over 1.4 billion people worldwide, and its sister species, Ascaris suum, has infected a countless number of domesticated and feral pigs. It is generally thought that the putative ancestor to these worms infected either humans or pigs, but with the advent of domestication, they had ample opportunity to jump to a new host and subsequently specialize and evolve into a new species. While nuclear DNA makers decisively separate the two populations, mitochondrial sequences reveal that three major haplotypes are found in A. suum and in A. lumbricoides, indicating either occasional hybridization, causing introgression of gene trees, or retention of polymorphism dating back to the original ancestral species. This article provides an illustration of the combined contribution of parasitology, archaeoparasitology, genetics and paleogenetics to the history of ascariasis. We specifically investigate the molecular history of ascariasis in humans by sequencing DNA from the eggs of Ascaris found among ancient archeological remains. The findings of this paleogenetic survey will explain whether the three mitochondrial haplotypes result from recent hybridization and introgression, due to intensive human-pig interaction, or whether their co-occurrence predates pig husbandry, perhaps dating back to the common ancestor. We hope to show how human-pig interaction has shaped the recent evolutionary history of this disease, perhaps revealing the identify of the ancestral host.

New Genera and Species of Psychodoid Flies from the Lower Cretaceous Amber Lebanon

Until now, only two Psychodoidea were known from Lebanese amber. We describe two new genera and species of Phlebotomidae (Mesophlebotomites hennigi gen. et sp. nov., Libanophlebotomus lutfallahi gen. et sp. nov.) and four new genera with six new species of Psychodidae (Paleopsychoda solignaci gen. et sp. nov., Paleopsychoda jacquelinae sp. nov., Protopsychoda nadiae gen. et sp. nov., Protopsychoda hammanaensis sp. nov., Libanopsychoda abillamai gen. et sp. nov., Cretapsychoda inexpectata gen. et sp. nov.) from the Lower Cretaceous amber of Hammana/Mdeirij, Lebanon. These fossils are included in a phylogenetic analysis of the subfamilies of Psychodoidea. This superfamily was probably as diverse in the Early Cretaceous as now.