caninum and T. gondii tissue cysts ( Weiss et al., 1999). For signal amplification, the avidin–biotin complex immunoperoxidase step was performed (DakoCytomation, Denmark) and the slides stained with diaminobenzidine tetrahydrochloride (DAB – DakoCytomation). Counter staining was performed with Harris hematoxylin (10%) and slides were later mounted on coverslips to be read under light microscope (Nikon, Japan). Direct detection was also attempted by the detection of Nc5 locus in the IHC positive samples, using DNA extraction, primer

sets and amplification protocols as previously described ( Furuta selleckchem et al., 2007). The need to observe N. caninum in wildlife animals has been pointed out as a possible way to understand some obscure aspects of the parasite’s cycle ( Gondim, 2006). There are indications that the presence of birds in cattle-raising farms could be associated with the increase of seroprevalence and abortions related to N. caninum ( Bartels et al., 1999 and Otranto

et al., 2003). In T. gondii epidemiological chain, birds are considered parasite’s reservoir, since those animals are frequently preyed upon by its definitive hosts, felids ( Elmore Selumetinib concentration et al., 2010). The same pattern of events may be observed in the relationship between dogs and birds, which may lead to speculations towards if birds may also perform the role of N. caninum reservoirs in nature. Epidemiological studies for these protozoa frequently employ antibody detection to estimate population infection rates. Serological positivity to T. gondii in birds is usually low, which is not compatible with direct detection in different tissues ( Dubey, 2002). Serological analysis by IFAT of samples gathered from wild birds maintained in captivity and free-ranging birds for the presence of antibodies to N. caninum were inconclusive, since specific IgG antibodies to N. caninum were not detected. The absence of detectable levels of specific IgG against N. caninum in birds is not a surprise, since it has been already shown that experimentally infected pigeons and different chicken models present

an abrupt antibody seroconversion, from despite a brief detection period ( Furuta et al., 2007 and Mineo et al., 2009). Additionally, the same phenomenon has been described in experimental infections of wild birds with T. gondii ( Mineo et al., 2009 and Vitaliano et al., 2010). The lack of detection of circulating antibodies specific to the parasite in the tested species may be partially attributed to the serological assay employed, which is based on a secondary antibody raised for chickens. Although the assay seems to work properly with some wildlife species, IgG domains of different bird species is variable and might not present the same homology with chicken antibodies, fact that may dampen the serological diagnosis in wild life animals. Unfortunately, it is uncommon to find commercial conjugates specific for wild life animals, which limits applied research focusing those species.