Background Toxoplasma gondii may cause abortions, ocular and neurological disorders in warm-blood hosts. Immunized mammals are a wide source of hyperimmune sera used in different approaches, including diagnosis and the study of host-parasite interactions. Unfortunately, mammalian antibodies present limitations for its production, such as the necessity for animal bleeding, low yield, interference with rheumatoid factor, complement activation and affinity to Fc mammalian receptors. IgY antibodies avoid those limitations; therefore they could be an alternative to be applied in T. gondii model.Methodology/Principal FindingsIn this study we immunized hens with soluble tachyzoite antigens of T. gondii (STAg) and purified egg yolk antibodies (IgY) by an inexpensive and simple method, with high yield and purity degree. IgY anti-STAg antibodies presented high avidity and were able to recognize a broad range of parasite antigens, although some marked differences were observed in reactivity profile between antibodies produced in immunized hens and mice. Interestingly, IgY antibodies against Neospora caninum and Eimeria spp. did not react to STAg. We also show that IgY antibodies were suitable to detect T. gondii forms in paraffin-embedded sections and culture cell monolayers.Conclusions/SignificanceDue to its cost-effectiveness, high production yield and varied range of possible applications, polyclonal IgY antibodies are useful tools for studies involving T. gondii.

Co x Fe 3 − x O 4 -based (x=0.05–1.6) nanoparticles prepared by combustion reaction were investigated using x-ray diffraction, Raman spectroscopy, and Mössbauer spectroscopy. The Mössbauer data revealed Co2+ in both tetrahedral (site A) and octahedral (site B) sites of the cubic ferrite structure. For x⩽0.4 the experimental data indicated the synthesis of a core-shell structure, with hematite as the shell and cobalt ferrite as the core of the nanoparticle. Differences in crystalline structure between the two phases support the evidences we found of a highly stressed core-shell interface, leading to symmetry reduction of the tetrahedral and octahedral sites.

The prevalence of Leptospirosis in goat herds of the State of Minas Gerais has seldom been studied. The present research had as its objectives: (1) investigate the seroprevalence of Leptospirosis in the county of Uberlândia, MG, (2) verify the Leptospirosis serovars, and (3) identify the risk factors associated with infection on the farms examined. Serum samples from 230 animals in 11 properties were tested using the microscopic agglutination test. An epidemiological examination furnished data for analysis regarding the risk factors. The prevalence of Leptospirosis was found to be 31.3% with variation from 1:100 to 1:800. The most frequent serovars were: Autumnalis (30.30%), Tarassovi (19.20%), Pyrogenes (13.13%), and Icterohaemorrhagiae (11.11%). The ages and races of the animals were among the risk factors found to be significantly correlated (P<0.05) with infection. At the farm level, the intensity of production, use of salaried workers, and association of other animals were all found to be related with the frequency of Leptospirosis. The results demonstrated that inadequate management was a factor which favored the occurrence of infection in the region of the study.

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