Recovery of Toxoplasma gondii DNA in experimentally mummified skin and bones: Prospects for paleoparasitological studies to unveil the origin of toxoplasmosis.
Paleoparasitology studies parasite infections by finding the parasites' remains in preserved organic remains such as natural or artificial mummy tissues, skeletons, teeth, and coprolites, among others. However, some currently important infections like toxoplasmosis have not been studied by paleoparasitology. The reasons include this parasite's complex life cycle, the resulting difficulties in locating this protozoan in the intermediate host tissues, and the limitation of coprolite studies to felines, the protozoan's definitive host. The current study thus aimed to produce an experimental model for molecular diagnosis of toxoplasmosis, prioritizing its study in bones and skin, the most abundant materials in archeological collections and sites. The study demonstrated the feasibility of recovering Toxoplasma gondii DNA from desiccated material, including bones and skin, in experimental models both with circulating tachyzoites (RH strain), characteristic of acute infection, and with cysts (ME49 cystogenic strain), characteristic of chronic infection. At present, most individuals with T. gondii infection are in the chronic phase, and the same was probably true in the past. The current study thus expands the odds of finding the parasite in archeological material, enhanced by the nature of the material in which the diagnosis was made. Finding the parasite may help answer questions that are widely debated in the literature on this protozoan's origin (Old World versus New World). In addition, when conditions do not allow ideal storage of samples for molecular tests, the methodology creates the possibility of testing oven-dried samples transported at room temperature.
Laboratory of Parasite Molecular Biology, Department of Microbiology and Parasitology, Fluminense Federal University, Niterói, RJ, Brazil. Electronic address: dleles@id.uff.br.
Daniela
D
Leles
Laboratory of Paleoparasitology, Escola Nacional de Saúde Pública/Fiocruz, Rio de Janeiro, RJ, Brazil.
Amanda
A
Lobo
Laboratory of Parasite Molecular Biology, Department of Microbiology and Parasitology, Fluminense Federal University, Niterói, RJ, Brazil.
Taís
T
Rhodes
Laboratory of Parasite Molecular Biology, Department of Microbiology and Parasitology, Fluminense Federal University, Niterói, RJ, Brazil.
Patrícia Riddell
PR
Millar
Laboratory of Toxoplasmosis and Other Protozoan Infections, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, RJ, Brazil.
Maria Regina Reis
MR
Amendoeira
Laboratory of Paleoparasitology, Escola Nacional de Saúde Pública/Fiocruz, Rio de Janeiro, RJ, Brazil.
Adauto
A
Araújo
D000818:Animals; D001842:Bone and Bones / Q000469:parasitology; D016054:DNA, Protozoan / Q000302:isolation & purification*; D049690:History, Ancient; D006801:Humans; D051379:Mice; D023421:Models, Animal; D009106:Mummies / Q000469:parasitology*; D012867:Skin / Q000469:parasitology; D014122:Toxoplasma / Q000235:genetics* / Q000302:isolation & purification; D014123:Toxoplasmosis / Q000266:history*
D016054:DNA, Protozoan
Ancient DNA; Bones; Diagnosis; Mummies; Toxoplasmosis