Ancient parasitic DNA reveals Toxascaris leonina presence in Final Pleistocene of South America.

Parasitological analysis of coprolites has allowed exploring ecological relationships in ancient times. Ancient DNA analysis contributes to the identification of coprolites and their parasites. Pleistocene mammalian carnivore coprolites were recovered from paleontological and archaeological site Peñas de las Trampas 1.1 in the southern Puna of Argentina. With the aim of exploring ancient ecological relationships, parasitological analysis was performed to one of them, dated to 16 573-17 002 calibrated years BP, with 95.4% probability. Parasite eggs attributed to Toxascaris sp. by morphological characters were isolated. DNA of coprolite and eggs was extracted to molecular identification. Ancient mitochondrial DNA analysis confirmed the zoological origin of the coprolite as Puma concolor and that of parasite eggs as Toxascaris leonina. This is the oldest molecular parasite record worldwide, and it supports the presence of this parasite since the Pleistocene in America. These findings have implications for the biogeographic history of parasites and for the natural history of the region.

Prevalence of Toxocara spp., Toxascaris leonina and ancylostomidae in public parks and beaches in different climate zones of Costa Rica.

This epidemiological study was conducted in different regions of Costa Rica to determine the prevalence of the developmental stages of potential zoonotic intestinal helminths of dogs and cats in public places. Samples were collected within three main climate zones including rural and urban areas during both the rainy and the dry season. Faecal and environmental samples were taken from 69 parks and beaches. Of the faecal samples 3% contained Toxascaris spp. eggs, 7% Toxocara spp. eggs and 55% contained ancylostomidae eggs. Of the soil samples, 2% contained ancylostomidae eggs and 0.8% contained ascarid eggs. Significant differences in the presence of parasites were found in faecal samples of dry, moist and wet climate zones and between the dry and rainy seasons. Significant differences in the presence of eggs and larvae were also found in the grass samples in the dry, the moist and the wet climate zones and between the different seasons. No significant differences were found between rural and urban areas.

Nematodes parásitos de dusycion griseus (Gray, 1837), D. culpaeus (Molina, 1782) y conepatus chinga (Molina, 1782) (mamífera: carnívora) en Neuquén, Argentina: sistemática y ecología / Parasites nematodes from dusycion griseus (Gray, 1837), D. culpaeus (Molina, 1782) and conepatus chinga (Molina, 1782) (mammalia: carnivora) in Neuquén, Argentina: systematics and ecology

Durante los períodos abril-agosto de 1989-1990 se examinaron los estómagos e intestinos de 129 ejemplares de Dusycion griseus, 22 de D. culpaeus y 22 de conepatus de la Provincia de Neuquén, Argentina. Se recolectaron cuatro especies de nematodes (Physaloptera clausa, Ph. maxillaris, Protospirura numidica criceticola y Toxascaris leonina). La posición sistemática de Ph. clausa Rudolphi, 1819, fue comentada habiendo concluído que representa a la especie tipo del género. Se consideró la posibilidad de que D. grisaseus y D. culpaeus fueran los hospedadores accidentales de la subespecie P. n. criceticola. Se dan los valores de prevalencia, intensidad media y frecuencia de cada especie en los hospedadores correspondientes. Se relacionaron esos valores con las dietas de cada hospedador y los ciclos de vida de los parásitos. Se determinó que la carga parasitaria de cada hospedador es independiente de su estado nutricional (prueba no paramétrica Tau de Kendall) y que existen diferencias significativas entre las dietas de los hospedadores y entre los valores de prevalencia, intensidad media y frecuencia de las especies parásitas (prueba de Chi cuadrado de Homogeneidad)