3. RESULTS AND DISCUSSION
The main gross findings were: purulent discharge in the right nostril extending to the frontal sinus; dental overgrowth of the lower right incisor associated with a solution of continuity in the maxillary and the right infraorbital regions, and marked congestion of the cortical blood vessels in the brain. No lesions were observed in other organs. Histologically, mild to moderate multifocal non-suppurative encephalitis, characterized by mononuclear perivascular cuffs with two to four layers of lymphocytes, plasma cells and macrophages, associated with mild to moderate multifocal gliosis, occasional necrosis of neuropil, randomly in white and gray matter. Multifocal protozoan cysts ranging from 66,3x44,9 microns to 126,7x136,0 microns, PAS positive, were observed (Figure 2). Protozoan cysts showed immunolabeling forT. gondii at IHC (Figure 2). Two protozoan cysts were found in the medulla of the adrenal gland.
In rodents (mainly mice and rats) is hypothesized that in latent infections, there is a neuroanatomical tendency of parasite cysts to be more abundant in amygdalar structures, resulting in impaired learning and memory and behavioral abnormalities, associated with loss of fear from predators, which could favor the biological cycle of the T. gondii (Hari Dass et al., 2014; Boillat et al 2020). In this porcupine, we observed T. gondii cysts exclusively in the central nervous system and in the medulla of the adrenal gland, the latter with a neuroectodermal origin. We believe that this case corresponds to a reactivation of latent infection due to the predominance of large cysts, rare inflammatory infiltrates around cystic structures, and absence ofToxoplasma gondii in other tissues, such as the liver and spleen.
Molecular confirmation through qPCR showed a moderate parasite load (Cq=30). In ToxoDB database platform, different genotypes (#1- #278) of T. gondii in human and animal samples are registered. This sample is likely a new genotype, with similarity to other known genotypes, since 9 out of 11 markers matched to ToxoDB PCR-RFLP genotypes #6, #80, #126 and #244 (Table 1). The genotype #6 (also known as BrI and Africa 1) is the major virulent lineage previously reported in Brazil, and it was previously identified in domestic and wild Brazilian animals like chickens, dogs, cats, sheep, goats, pigeons, and capybaras (Dubey et al., 2012; Costa et al., 2021; Barros et al., 2014; Yai et al., 2009). The genotype #6 is also observed in HIV-immunosuppressed humans in Brazil, with severe and diffuse cerebral toxoplasmosis (Ferreira et al., 2011). The genotypes #80 and #126 are described in Brazilian cats. Information about genotype #244 was not found in the literature. Beyond that, the only genotyping study on Sphiggurus spinosus , showed 4/7 markers similarity (Richini-Pereira et al., 2016).