Toxoplasma gondii in cetaceans of Brazil: a histopathological and immunohistochemical survey

• Published in: Revista Brasileira de Parasitologia Veterinária
• Main Authors: Samira Costa-Silva, Carlos Sacristán, Omar Gonzales-Viera, Josué Díaz-Delgado, Angélica María Sánchez-Sarmiento, Juliana Marigo, Kátia Regina Groch, Vitor Luz Carvalho, Ana Carolina Ewbank, Adriana Castaldo Colosio, Milton César Calzavara Marcondes, Ana Carolina Oliveira de Meirelles, Carolina P. Bertozzi, José Lailson-Brito, Alexandre de Freitas Azevedo, Valéria Ruoppolo, Larissa Oliveira, Paulo Henrique Ott, José Luiz Catão-Dias
• Format: Article in Journal/Newspaper
• Language: English; Spanish; Portuguese
• Published: Colégio Brasileiro de Parasitologia Veterinaria
• Subjects: Toxoplasmose; mortalidade; encalhe; América do Sul; infecção por protozoários; mamífero marinho; Animal culture; SF1-1100; Killer Whale; Orca; Orcinus orca; Killer whale
• Online Access: https://doi.org/10.1590/s1984-29612019051; https://doaj.org/article/8ac2fcaa49b3465b8d86bc3fcea87c90

Abstract Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. In cetaceans, T. gondii infection is a significant cause of morbidity and mortality. Despite the worldwide range and broad cetacean host record of T. gondii infection, there is limited information on toxoplasmosis in cetaceans from the Southern hemisphere. We investigated the occurrence of T. gondii by histopathology and immunohistochemistry in tissue samples of 185 animals comprising 20 different cetacean species from Brazil. Three out of 185 (1.6%) animals presented T. gondii-associated lesions: a captive killer whale Orcinus orca, a free-ranging common bottlenose dolphin Tursiops truncatus and a free-ranging Guiana dolphin Sotalia guianensis. The main lesions observed in these animals were necrotizing hepatitis, adrenalitis and lymphadenitis associated with protozoal cysts or extracellular tachyzoites presenting immunolabeling with anti-T. gondii antibodies. This study widens the spectrum of species and the geographic range of this agent in Brazil, and provides the first reports of T. gondii infection in a captive killer whale and in a free-ranging common bottlenose dolphin in South America.