Investigation of soil contaminated with Toxoplasma gondii oocyst in urban public environment, in Brazil.

In this study, we determined the occurrence of Toxoplasma gondii oocysts in soil samples from public places. A total of 120 samples were collected from 24 sites, including squares, parks, university, hospitals in the city of Recife. The recovered oocysts were subjected to a nested-PCR test, and nine sites (9/24) were found to be positive for gene of apicomplexan parasites. The PCR product was sequenced, and 8.33% (10/120) of the samples showed 100% similarity to T. gondii DNA. T. gondii oocysts were detected in 75% (3/4) of the evaluated hospital soil samples and in 23.81% (5/21) soils samples from the public squares and parks. The results of this study demonstrate the potential of the soil in the areas analyzed as a source of T. gondii infection and therefore highlight the importance of devising educational strategies on the use of these sites, in addition to future cleaning protocols in public areas.

Water potential in soil and Atriplex nummularia (phytoremediator halophyte) under drought and salt stresses.

Atriplex nummularia is a halophyte widely employed to recover saline soils and was used as a model to evaluate the water potentials in the soil-plant system under drought and salt stresses. Potted plants grown under 70 and 37% of field capacity irrigated with solutions of NaCl and of a mixture of NaCl, KCl, MgCl2 and CaCl2 reproducing six electrical conductivity (EC): 0, 5, 10, 20, 30, and 40 dS m-1. After 100 days, total water (Ψw, plant) and osmotic (Ψo, plant) potentials at predawn and midday and Ψo, soil, matric potential (Ψm, soil) and Ψw, soil were determined. The type of ion in the irrigation water did not influence the soil potential, but was altered by EC. The soil Ψo component was the largest contributor to Ψw, soil. Atriplex is surviving ECs close to 40 dS m-1 due to the decrease in the Ψw. The plants reached a Ψw of approximately -8 MPa. The water potentials determined for different moisture levels, EC levels and salt types showed huge importance for the management of this species in semiarid regions and can be used to recover salt affected soils.