1. INTRODUCTION
Toxoplasma gondii (T. gondii) may be the most successful parasite in the world, as it has a global distribution and can infect almost all warm-blooded animal species (Su et al., 2010; Dubey, 2010; Robert-Gangneux et al., 2012). Infections occur by ingestion or transplacentally (Dubey, 2010). Felids are their only definitive host (Vitaliano et al., 2014). Recent molecular studies have revealed a genotype diversity worldwide, with the largest genetic diversity in South America (Robert-Gangneux et al., 2012), specifically in Brazil (Pena et al., 2011), with reports of strains with resistance to sulfadiazine and pyrimethamine in human treatments (Bessa et al., 2021). Among the intermediate hosts, rodents (order Rodentia) play an important role in maintaining the life cycle of T. gondii , as they are one of the main food sources for wild felids (Galeh et al., 2021; Brito Jr et al., 2020; Horta et al., 2018; Gennari et al., 2015). Although histopathological lesions induced by T. gondii in rodents and other animals are suggestive of the disease, their morphological similarities with other apicomplexa require additional diagnostic tests, such as molecular and immunohistochemical exams (Harrison et al., 2007; Gardner, Payer et al., 1999).
South American porcupines belong to the Erethizontidae family. Their weight can reach up to 5 kg, and they are known for their prehensile tail used to carry out their daily activities, mainly in trees. Their diets are mainly based on leaves, fruits, and bark (Roze, 2012). The hairy dwarf porcupine Sphiggurus spinosus (F. Cuvier, 1823) has a wide distribution in northeastern Argentina, southeastern Brazil, eastern Paraguay, and northern Uruguay (Barthelmess et al., 2016; Voss, 2015). This species is found in a wide range of Brazilian habitats, including the Cerrado, the Pantanal, and the Atlantic Forest. This species is categorized as Least Concern (LC) according to the red list of the International Union for Conservation of Nature (IUCN) and has been included in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix III since 1976. Although the South American porcupines have a continental distribution due to their cryptic habits, the knowledge about their ecological and sanitary aspects is limited. This study reports the microscopic, immunohistochemical, and molecular features of toxoplasmosis in a free-ranging hairy dwarf porcupine in Brazil.
Among reports of toxoplasmosis in porcupines, Morales, Peña, and Dubey (1996) confirmed the first T. gondii in neotropical porcupines through histopathological and IHC analysis in a captive Sphiggurus mexicanus in Costa Rica. There are also reports in a Hystrix cristata (Harrison et al., 2007), three Chaetomys subspinasusfrom Brazil (Bezerra et al., 2015), and one Erethizontidae sp. in Germany (Fayyad et al., 2017).