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

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.

Fatal pulmonary parafilaroidiasis in a free-ranging subantarctic fur seal (Arctocephalus tropicalis) coinfected with two gammaherpesviruses and Sarcocystis sp.

A juvenile subantarctic fur seal (Arctocephalus tropicalis) found dead in Santa Catarina state, southern Brazil, presented with disseminated verminous pneumonia due to Parafilaroides sp. A concomitant infection with two different gammaherpesviruses was identified by PCR in different tissues; one of them possibly a novel species (tentatively named Otariid herpesvirus 7). Sarcocystis sp. DNA was identified molecularly in skeletal muscle samples with intrasarcoplasmic bradyzoites and no apparent tissue response. All analyzed samples (mandibular, laryngeal, tracheal, and mesenteric lymph nodes, and lung) were PCR-negative for Brucella spp. The most likely cause of death was severe pulmonary parafilaroidiasis. The pathogenic role of the gammaherpesviruses in several of the tissues was not evident. This study describes the pathogenicity of Parafilaroides sp. in a subantarctic fur seal, widens the host range of herpesvirus in pinnipeds, and reports the first molecular identification of Sarcocystis sp. in this species.

Fatal pulmonary parafilaroidiasis in a free-ranging subantarctic fur seal (Arctocephalus tropicalis) coinfected with two gammaherpesviruses and Sarcocystis sp / Parafilaroidose pulmonar fatal em um lobo-marinho-subantártico (Arctocephalus tropicalis) de vida livre coinfectado com dois gammaherpesvírus e Sarcocystis sp

Abstract A juvenile subantarctic fur seal (Arctocephalus tropicalis) found dead in Santa Catarina state, southern Brazil, presented with disseminated verminous pneumonia due to Parafilaroides sp. A concomitant infection with two different gammaherpesviruses was identified by PCR in different tissues; one of them possibly a novel species (tentatively named Otariid herpesvirus 7). Sarcocystis sp. DNA was identified molecularly in skeletal muscle samples with intrasarcoplasmic bradyzoites and no apparent tissue response. All analyzed samples (mandibular, laryngeal, tracheal, and mesenteric lymph nodes, and lung) were PCR-negative for Brucella spp. The most likely cause of death was severe pulmonary parafilaroidiasis. The pathogenic role of the gammaherpesviruses in several of the tissues was not evident. This study describes the pathogenicity of Parafilaroides sp. in a subantarctic fur seal, widens the host range of herpesvirus in pinnipeds, and reports the first molecular identification of Sarcocystis sp. in this species.

Resumo Um lobo-marinho-subantártico (Arctocephalus tropicalis) juvenil foi achado morto no Estado de Santa Catarina, sul do Brasil, apresentando pneumonia parasitária disseminada por Parafilaroides sp. Infecção concomitante por dois gammaherpesvírus diferentes foi identificada pela PCR em diversos tecidos, um desses herpesvírus possivelmente uma nova espécie (denominada provisoriamente Otariid herpesvirus 7). DNA de Sarcocystis sp. foi identificado molecularmente em amostras de músculo esquelético que apresentavam bradizoítos intra-sarcoplasmáticos sem aparente resposta tecidual. Todas as amostras analisadas (linfonodo mandibular, laríngeo, traqueal e mesentérico, e pulmão) pela PCR para Brucella spp. foram negativas. A causa mais provável da morte do animal foi parafilaroidose pulmonar severa. O papel patogénico dos gammaherpesvírus em vários tecidos não foi evidente. Este estudo descreve a patogenicidade de Parafilaroides sp. em um lobo-marinho-subantártico, amplia a variedade de hospedeiros de herpesvírus em pinípedes e reporta a primeira identificação molecular de Sarcocystis sp. para essa espécie.

Toxoplasma gondii in cetaceans of Brazil: a histopathological and immunohistochemical survey / Toxoplasma gondii em cetáceos do Brasil: estudo histopatológico e imuno-histoquímico

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.

Resumo Toxoplasmose é uma doença parasitária causada pelo protozoário Toxoplasma gondii. A infecção por T. gondii é uma causa significativa de morbidade e mortalidade, nos cetáceos. Apesar da abrangência mundial e amplo registro de espécies de cetáceos infectadas por T. gondii, informações sobre toxoplasmose em cetáceos do hemisfério sul são limitadas. Neste estudo pesquisou-se por meio de histopatologia e imuno-histoquímica a ocorrência de T. gondii em amostras de tecido de 185 animais, compreendendo 20 diferentes espécies de cetáceos que ocorrem no Brasil. Três dos 185 (1,6%) animais apresentaram lesões associadas a T. gondii: uma orca Orcinus orca mantida em cativeiro, um golfinho-nariz-de-garrafa Tursiops truncatus e um boto-cinza Sotalia guianensis de vida livre. As principais lesões observadas nesses animais foram hepatite, adrenalite e linfadenite necrotizantes associadas a cistos protozoários ou taquizoítos extracelulares, marcados com anticorpos anti-T. gondii. O presente estudo amplia o espectro de espécies susceptíveis a esse agente e o seu alcance geográfico no Brasil, fornecendo o primeiro relato da infecção por T. gondii em uma orca mantida em cativeiro e em um golfinho-nariz-de-garrafa de vida livre na América do Sul.

Molecular identification and microscopic characterization of poxvirus in a Guiana dolphin and a common bottlenose dolphin, Brazil.

The poxviruses identified in cetaceans are associated with characteristic tattoo or ring skin lesions. However, little is known regarding the prevalence and progression of these lesions and the molecular characterization of cetacean poxviruses in the Southern Hemisphere. This manuscript describes the progression of poxvirus-like skin lesions in 5 free-ranging Guiana dolphins Sotalia guianensis. Additionally, 151 skin samples from 113 free-ranging cetaceans from Brazil, including 4 animals with tattoo skin lesions, were selected for poxvirus testing. Poxviral DNA polymerase gene PCR amplification was used to detect the virus in ß-actin-positive samples (145/151). DNA topoisomerase I gene PCR was then used in Cetaceanpoxvirus (CePV)-positive cases (n = 2), which were further evaluated by histopathology and electron microscopy. Based on photo-identification, adult Guiana dolphins presented regressing or healed poxvirus-like lesions (2/2), while juveniles presented persistent (2/3) or healed and progressive lesions (1/3). CePV DNA was amplified in a common bottlenose dolphin Tursiops truncatus and in a Guiana dolphin. Intracytoplasmic inclusion bodies and viral particles consistent with poxvirus were identified by histology and electron microscopy, respectively. CePV-specific amino acid motifs were identified through phylogenetic analysis. Our findings corroborate previous studies that suggest the placement of poxviruses from cetaceans within the novel CePV genus. This is the first molecular identification of poxvirus in South American odontocetes.

Pathology and causes of death in stranded humpback whales (Megaptera novaeangliae) from Brazil.

This study describes the pathologic findings of 24 humpback whales (Megaptera novaeangliae) found stranded along the Brazilian coast from 2004 to 2016. Eighteen (75%) animals evaluated were found stranded alive. From these, 13 died naturally on shore and five were euthanized. Six died at sea and were washed ashore. Of the 24, 19 (79.2%) were calves, four (16.7%) were juveniles, and one (4.2%) was an adult. The most probable cause of stranding and/or death (CSD) was determined in 23/24 (95.8%) individuals. In calves, CSD included neonatal respiratory distress (13/19; 68.4%), infectious disease (septicemia, omphaloarteritis and urachocystitis; 3/19; 15.8%), trauma of unknown origin (2/19; 10.5%), and vehicular trauma (vessel strike; 1/19; 5.3%). In juveniles and adult individuals, CSD was: emaciation (2/5; 40%), sunlight-thermal burn shock (1/5; 20%); and discospondylitis (1/5; 20%). In one juvenile, the CSD was undetermined (1/5; 20%). This study integrates novel findings and published case reports to delineate the pathology of a South-western Atlantic population of humpback whales. This foundation will aid in the assessment of the population health and establish a baseline for development of conservation policies.

Histological aspects of the mucosa of the spermaceti chamber of a dwarf sperm whale / Aspectos histológicos da mucosa da câmera do espermacete de cachalote-anão

The sound producing apparatus of the dwarf sperm whale (Kogia sima) presents a complex anatomic structure composed of melon, spermaceti, phonic lips, vocal cap, case, papillae, spermaceti chamber and other airspaces, as well as facial muscles involved in sound production. The spermaceti chamber rests on the caudal portion of the premaxilla, with part of its mucosa covered with spherical/oval-shaped structures (approximately 1 to 2 mm in diameter), compatible with vesicles (previously referred to as "papillae"). Macroscopical examination revealed whitish, firm, widely and irregularly distributed vesicular mucosa on the premaxillary portion of the spermaceti chamber of a K. sima specimen stranded on the coast of Santos (southeastern Brazilian coast). Upon microscopic examination, walls of connective tissue with abundant type I collagen forming vesicles with an internal space or cavity filled with a small amount of eosinophilic substance compatible with mucoproteic fluid were observed. The base of such vesicles presented glands within the connective tissue, probably responsible for fluid production. This study describes the histology of the mucosa of the spermaceti chamber of a K. sima specimen and characterizes the glands associated with fluid production.(AU)

O sistema de produção sonora do cachalote-anão (Kogia sima) apresenta uma complexa estrutura anatômica composta por melão, espermacete, lábios fônicos, "vocal cap", "case", papilas, câmara do espermacete e outros espaços aéreos, além de músculos faciais envolvidos na produção sonora. A câmara do espermacete localiza-se na porção caudal da pré-maxila, apresentando parte de sua mucosa recoberta por estruturas esférico-ovaladas de aproximadamente 1 a 2 mm de diâmetro, compatíveis com vesículas (previamente denominadas "papilas"). Ao exame macroscópico de um espécime de K. sima encalhado no litoral de Santos (sudeste da costa brasileira), foi identificada mucosa esbranquiçada e firme ao corte, ampla e irregularmente distribuída na porção pré-maxilar da câmara do espermacete. Ao exame microscópico foram observadas vesículas compostas por abundante tecido conectivo de colágeno tipo I, dando origem a um espaço interno ou cavidade, contendo pequena quantidade de substância eosinófila, compatível com fluido mucoprotêico. Estruturas glandulares foram observadas em tecido conjuntivo na base das vesículas, provavelmente responsáveis pela produção do fluido observado no interior das mesmas. Esse estudo caracteriza histologicamente a mucosa da câmara do espermacete de um espécime de K. sima e as glândulas relacionadas a sua produção secretória.(AU)