Lutz's spontaneous sedimentation technique and the paleoparasitological analysis of sambaqui (shell mound) sediments

Parasite findings in sambaquis (shell mounds) are scarce. Although the 121 shell mound samples were previously analysed in our laboratory, we only recently obtained the first positive results. In the sambaqui of Guapi, Rio de Janeiro, Brazil, paleoparasitological analysis was performed on sediment samples collected from various archaeological layers, including the superficial layer as a control. Eggs of Acanthocephala, Ascaridoidea and Heterakoidea were found in the archaeological layers. We applied various techniques and concluded that Lutz's spontaneous sedimentation technique is effective for concentrating parasite eggs in sambaqui soil for microscopic analysis.

Is nematode colonisation in the presence of Scolelepis in tropical sandy-beach sediment similar to the colonisation process in temperate sandy beaches? / A colonização dos sedimentos de praias tropicais por nematódeos na presença de Scolelepis é similar ao processo de colonização que ocorre em praias arenosas temperadas?

The role of a dominant macrobenthic polychaete, Scolelepis squamata, in the colonisation of defaunated tropical sediments by sandy-beach nematodes was investigated and compared with a previous colonisation experiment carried out on a temperate sandy beach. Experimental cylinders, equipped with lateral windows allowing infaunal colonisation, were filled with defaunated sediment containing two treatments, with and without S. squamata. These cylinders were inserted into microcosms containing sediment with indigenous meiofauna collected from the field. The treatments were incubated in the laboratory at ambient temperature and salinity for 7, 14 and 21 days. The nematode assemblages in both treatments did not differ in composition between treatments and from the natural assemblages, suggesting that all the species were equally able to colonise the experimental cores. The presence of the polychaete did not affect the development of the nematode community composition, in contrast to the results from a previous temperate-beach experiment. However, our results did not indicate whether the difference in results was caused by the different behaviour of the polychaete specimens, or by the different composition and response of the present nematode community.

Esse estudo avaliou a influência da espécie Scolelepis squamata (Polychaeta) no processo de colonização de sedimentos defaunados obtidos em uma praia arenosa tropical, além de comparar esses resultados com um estudo similar realizado em uma praia temperada. Sedimentos, previamente defaunados, foram colocados em amostradores com aberturas laterais, que permitiram a colonização da meiofauna. Foram definidos dois tratamentos, um com a presença e outro com a ausência da espécie S. squamata, além do controle. Os amostradores desses tratamentos foram alocados em unidades experimentais do tipo microcosmo, as quais continham sedimento com a meiofauna residente. Os tratamentos foram incubados em laboratório por 7, 14 e 21 dias, com condições controladas de temperatura e salinidade. Os nematódeos não apresentaram diferenças significativas em termos de composição entre os tratamentos e nem em relação ao controle, sugerindo que todas as espécies desse grupo foram, igualmente, capazes de colonizar as unidades experimentais. Esses resultados indicaram que a presença do poliqueto não afetou a estrutura da comunidade de nematódeos, o que representou um resultado contrário ao obtido para a praia temperada. No entanto, não se pode concluir se essas diferenças entre as praias estariam relacionadas ao comportamento diferencial de S. squamata ou pela presença de comunidades de nematódeos distintas nas praias.

Resíduos alimentares, infecções parasitárias e evidência do uso de plantas medicinais em grupos pré-históricos das Américas / Food waste, parasitic infections and evidence of the use of medicinal plants in groups of prehistoric Americas

A paleoparasitologia utiliza como principal instrumento de estudo a análise de coprólitos e sedimentos retirados do solo de sítios arqueológicos, latrinas e da área pélvica de esqueletos. Associando-se dados da arqueologia, antropologia e paleoparasitologia, entre outras ciências, é possível obter resultados consistentes sobre modo de vida e saúde das populações no passado. Neste trabalho foram analisadas amostras de três regiões diferentes das Américas. Um total de 59 amostras de coprólitos e sedimentos provenientes de sítios arqueológicos localizados na área arqueológica de São Raimundo Nonato, que engloba o Parque Nacional Serra da Capivara (PNSC), Piauí, Brasil, foram analisadas. Esta região apresenta sítios com datações bastante antigas obtidas na área do Parque, com evidência de atividades humanas datadas aproximadamente de 50.000 anos; 12 amostras provenientes do sítio arqueológico Antelope Cave, localizado no Arizona, EUA. Assim como o PNSC, este sítio possui a presença de cerâmica e a iniciação da agricultura pelos grupos pré-históricos naquela região; e 15 amostras retiradas diretamente da região pélvica de sepultamentos provenientes do sambaqui Cubatão I, localizado em Joinville, Santa Catarina, Brasil. Este sítio arqueológico é, na verdade, um desafio metodológico devido ao clima e a atividade biótica do solo da região que não permitem boas condições de preservação do material arqueológico. A análise de resíduos alimentares destas diferentes regiões arqueológicas forneceu dados a respeito da dieta de populações antigas e a relação entre a presença de parasitos e o encontro de plantas com propriedades anti-helmínticas, e ainda foi possível a determinação de casos de falso parasitismo.

Paleoparasitology uses, as the main tool to study, the analysis of coprolites andsediments removed from the land of archaeological sites, latrines and the pelvic area of skeletons. Joining data from archeology, anthropology and paleoparasitology, among other sciences, it is possible to obtain solid results on livelihoods and health of people in the past. On this study were analyzed samples from three different regions of the Americas. A total of 59 samples of coprolites and sediments from archaeological sites located in thearchaeological area of São Raimundo Nonato, which includes the National Park Serra da Capivara (PNSC), located in Pernambuco, Brazil, were analyzed. This region has sites with the oldest dating obtained in the Park, with human activities recorded from 50.000 years BP; 12 samples from the archaeological site of Antelope Cave, located in Arizona, USA. This site, just like PNSC, has features such as the presence of pottery and the initiation of agriculture by prehistoric groups in the region, and 15 samples taken directly from the pelvic region of burials from the sambaqui Cubatão I, located in Joinville, Santa Catarina, Brazil. This archaeological site is actually a methodological challenge due to the climate and soil biotic activity in the region that don't allow good conditions of preservation of the archeological material. The analysis of alimentary residues of these different archaeological areas supplied dataregarding the diet of old populations and the relationship between the presence ofparasites and the encounter of plants with anthelminthic properties, and it was still possible the determination of cases of false parasitism.

Quantitative paleoparasitology applied to archaeological sediments

Three techniques to extract parasite remains from archaeological sediments were tested. The aim was to improve the sensibility of recommended paleoparasitological techniques applied in archaeological remains. Sediment collected from the pelvic girdle of a human body found in Cabo Vírgenes, Santa Cruz, Argentina, associated to a Spanish settlement founded in 1584 known as Nombre de Jesús, was used to search for parasites. Sediment close to the skull was used as control. The techniques recommended by Jones, Reinhard, and Dittmar and Teejen were used and compared with the modified technique presented here, developed to improve the sensibility to detect parasite remains. Positive results were obtained only with the modified technique, resulting in the finding of Trichuris trichiura eggs in the sediment.

Genetic diversity of Acanthamoeba isolated from ocean sediments

Genetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their cytopathic effects on human corneal epithelial cells versus reference strains. All isolates belonged to morphologic group II. Total of 16 restriction phenotypes of mtDNA from 18 isolates demonstrated the genetic diversity of Acanthamoeba in ocean sediments. Phylogenetic analysis using 18s rDNA sequences revealed that the 18 isolates were distinct from morphological groups I and III. Fifteen isolates showed close relatedness with 17 clinical isolates and A. castellanii Castellani and formed a lineage equivalent to T4 genotype of Byers' group. Two reference strains from ocean sediment, A. hatchetti BH-2 and A. griffini S-7 clustered unequivocally with these 15 isolates. Diversity among isolates was also evident from their cytopathic effects on human corneal cells. This is the first time describing Acanthamoeba diversity in ocean sediments in Korea.