Lesions caused by Sarcocystis spp., parasites of opossums (Didelphis aurita), in acute and chronic infections in birds (Melopsittacus undulatus).

Protozoa of the genus Sarcocystis are obligatory heterogenous parasites with both definitive and intermediate hosts. Opossums (Didelphis aurita) can shed multiple species of Sarcocystis with birds as the intermediate host. The pathologies of Sarcocystis species in birds have not been thoroughly elucidated. Therefore, the aim of the present study to determine the main lesions that can occur in acute and chronic infections in intermediate hosts, when they ingest infective sporocysts that are shed in the opossum's feces, using budgerigars as a model. To this end, 12 budgerigars, Melopsittacus undulatus, were divided into two groups that received an inoculum with 60 and 120 sporocysts. Birds that died or were euthanized were necropsied, and the lung, tongue, liver, brain, heart, and skeletal striated muscles were collected and fixed in 10% formalin for histopathological analysis. The infectivity varied according to the sample and infective dose. Acute histopathological lesions were characterized by evidence of slightly degenerated hepatocyte cords that permeated the region of the blood vessel and hepatic sinusoids. Pulmonary tissue lesions were also observed in the parabronchial region with the presence of inflammatory infiltrates associated with areas of edema and atelectasis. In chronic infections, few mature cysts were observed in the chest, and many mature cysts in the thigh and tongue muscles. Thus, it was possible to conclude that lesions are highly characteristic in acute infection and, in chronic infections, cysts were present but without major lesions. In this case, the preferred organs of parasitism were the thigh and the tongue.

First report of Diplostomidae metacercariae (Trematoda: Digenea) in African catfish Clarias gariepinus (Siluriformes: Clariidae) in Brazil / Primeiro relato de metacercárias de Diplostomidae (Trematoda: Digenea) em bagre africano Clarias gariepinus (Siluriformes, Clariidae) no Brasil

Abstract Clarias gariepinus is a fish from North of South Africa and was later introduced in several countries, including Brazil. The present study aimed to describe the first report of Diplostomidae metacercariae in C. gariepinus in Brazil. For this, 30 C. gariepinus were captured in a lake in the city of Campos dos Goytacazes, RJ, Brazil. Fishes were euthanized using freezing and necropsied for collection of parasites. The organs were dissected and analyzed for the presence of parasites that were processed for light and scanning electron microscopy. Trematodes were stained with Semichon's Carmine and Gomori's Trichrome, observed and schematized under a light microscope with image analysis software. A total of 190 trematodes were collected from the gills, suprabranchial organs, heart, stomach, intestinal mesentery, liver and body cavity of the fish. The parasites had a foliaceous body divided by a discrete constriction, without genital primordia, and a holdfast organ present at the posterior region, typical of metacercariae of the family Diplostomidae. It was classified as the 'Diplostomulum' morphotype, based on the morphology of the reserve bladder structure. This is the first report of the metacercariae of Diplostomidae parasitizing C. gariepinus in the Americas. This fish acts as an intermediate or paratenic host of this digenean in Brazil.

Resumo Clarias gariepinus é um peixe do Norte da África do Sul e posteriormente introduzido em diversos países, incluindo o Brasil. O presente estudo teve como objetivo descrever o primeiro relato de metacercárias em C. gariepinus no Brasil. Para tanto, 30 C. gariepinus foram capturados em um lago na cidade de Campos dos Goytacazes, RJ, Brasil. Os peixes foram eutanasiados por congelamento e necropsiados para a coleta de parasitos. Os órgãos foram dissecados e analisados para a presença de parasitos que foram processados para microscopia ótica e electronica de varredura. Os Trematodeos foram corados com carmim de Semichon e tricrômico de Gomori, observados e esquematizados sob microscópio ótico equipado com software de análise de imagens. Um total de 190 trematodeos foram coletados das brânquias, órgãos suprabrânquiais, coração, estômago, mesentério intestinal, fígado e cavidade corporal dos peixes. Os parasitos tinham corpo foliáceo, dividido por uma discrete contrição, sem primórdio genital, e órgão tribocítico presente na região posterior, típico das metacercárias da fámilia Diplostomidae. Foram classificados como do morfotipo 'Diplostomulum', baseado na morfologia da estrutura da bexiga de reserva. Este é o primeiro relato de metacercárias de Diplostomidae parasitando C. gariepinus nas Américas. Este peixe atua como hospedeiro intermediário ou paratênico deste Digenea no Brasil.

Identification of opossums Didelphis aurita (Wied-Neuweid, 1826) as a definitive host of Sarcocystis falcatula-like sporocysts.

This study was conducted to identify the Sarcocystis species that infect the opossum Didelphis aurita in order to determine which sporocysts they are excreating in to the environment and help determine the role of D. aurita in the epidemiology of Sarcocystis. Sporocysts were obtained from intestinal tracts of 8 of 13 D. aurita trapped in Rio de Janeiro state, Brazil, and were orally inoculated into Melopsittacus undulatus and Balb/c nude Mus musculus. Portions of organs and muscles were processed for histology, immunohistochemistry, transmission electron microscopy (TEM), and PCR using primers JNB 33/54, and ITS. Amplification products were subjected to RFLP using DraI and HinfI. Some birds were euthanized 6, 7, 13, 16, and 24 days after inoculation (DAI). All other birds and all mice were euthanized 60 DAI. Schizonts were observed in the lungs using histology and immunostaining in birds examined prior to 60 DAI. Sarcocysts with a ~ 1.5-µm-thick wall were found in the breast, thigh, and tongue of some birds. Sarcocystis asexual stages were isolated in cell cultures inoculated with sporozoites. Parasite DNA isolated from bird tissues and cell cultures demonstrated that S. falcatula-like parasites were present in all samples derived from positive opossums. Asexual stages molecularly characterized as S. lindsayi-like were isolated in cell culture from one opossum with an apparent multiple infection. This study demonstrated that D. aurita is a definitive host for S. falcatula-like parasites and indicates that S. lindsayi-like parasites can be found in coinfections of this opossum species.

Gastrointestinal nematodes in ostriches, Struthio camelus, in different regions of the state of Rio de Janeiro, Brazil / Nematoides gastrintestinais em avestruzes, Struthio camelus, de diferentes regiões do Estado do Rio de Janeiro, Brasil

The ratite group is composed of ostriches, rheas, emus, cassowaries and kiwis. Little research has been done on parasitism in these birds. The aim of this study was to determine the distribution of infections by gastrointestinal nematodes in ostriches in the state of Rio de Janeiro. For this, fecal samples were collected from 192 on 13 farms. From each sample, four grams of feces were used to determine the eggs per gram of feces (EPG) count, by means of the McMaster technique. Part of the feces sample was used for fecal cultures, to identify 100 larvae per sample. The results were subjected to descriptive central trend and dispersion analysis, using confidence intervals at the 5% error probability level in accordance with the Student t distribution, and Tukey’s test with a 95% confidence interval. The mean EPG in the state was 1,557, and the municipality of Três Rios had the lowest average (62). The city of Campos dos Goytacazes presented the highest mean EPG of all the municipalities analyzed. The northern region presented the highest mean EPG, followed by the southern, metropolitan, coastal lowland and central regions. Libyostrongylus species were observed on all the farms: L. douglassii predominated, followed by L. dentatus and Codiostomum struthionis. .

O grupo das ratitas é composto pelas avestruzes, emas, emús, cassuares e kiwi. São poucas as pesquisas sobre as parasitoses nessas aves. O objetivo deste estudo foi determinar a distribuição de infecções por nematóides gastrintestinais em avestruzes no Estado do Rio de Janeiro. Para tanto, foram coletadas amostras fecais de 192 avestruzes de 13 propriedades. De cada amostra, quatro gramas foram utilizados para a contagem de ovos por grama de fezes (OPG), pela da técnica de McMaster. Parte das fezes foi utilizada para cultivos fecais para identificação de 100 larvas por amostra. Os resultados foram submetidos à análise descritiva de tendência central e de dispersão, utilizando-se o intervalo de confiança ao nível de 5% de probabilidade de erro de acordo com a distribuição t de Student e teste de Tukey com intervalo de confiança de 95%. A média de OPG no Estado foi de 1.557, e o município de Três Rios obteve a menor média (62). A cidade de Campos dos Goytacazes teve a maior média de OPG de todos os municípios analisados. A Região Norte teve a maior média de OPG, seguida das regiões Sul, Metropolitana, Baixada Litorânea e Central. As espécies de Libyostrongylus foram observadas em todas as propriedades, predominando L. douglassii, seguido de L. dentatus e Codiostomum struthionis.

Comparative morphology of the species of Libyostrongylus and Codiostomum, parasites from ostriches, Struthio camelus, with a identification key to the species / Morfologia Comparativa das espécies de Libyostrongylus e Codiostomum, parasitas de avestruzes, Struthio camelus, com uma chave para identificação das espécies

One of the most common problems in breeding of ostriches in captivity is the control of parasitic diseases. This work presents keys for the identification of adult nematodes and infective larvae by morphologic and morphometric characteristics. These keys will allow the scientific community to identify the species that infect the ostriches either based on the characteristics of the posterior end of the infective larvae found through a simple fecal exam or by observing the morphology and morphometry of adult worms recovered during necropsies. These keys will facilitate ecological and systematic studies, as well as increase the understanding of the epidemiology of these parasitosis in ostriches.

Um dos problemas mais comuns na criação de avestruzes em cativeiro é o controle das doenças parasitárias. Este trabalho apresenta chaves para a identificação de Nematoda adultos e larvas infectantes através de caracteres morfológicos e morfométricos. Essas chaves de identificação permitirão à comunidade científica o diagnóstico das espécies que infectam as avestruzes com base nas características da extremidade posterior das larvas infectantes encontradas por meio de simples exames fecais ou pela observação da morfologia e morfometria dos espécimes adultos recuperados durante necropsia. Dessa forma, as chaves de identificação facilitarão os estudos ecológicos e sistemáticos, bem como a melhor compreensão da epidemiologia dessas infecções em avestruzes.

Didelphis aurita (Marsupialia: Didelphidae): a new host for Sarcocystis lindsayi (Apicomplexa: Sarcocystidae).

Nine opossums, Didelphis aurita , were captured in the city of Seropédica, State of Rio de Janeiro, Brazil and examined for species of Sarcocystis. Sporocysts were observed in the mucosal scrapings of the small intestine from 3 opossums. Five budgerigars, Melopsittacus undulatus , were infected with sporocysts from each of these infected opossums and 5 budgerigars were used as controls. Of the 15 sporocyst-treated budgerigars, 5 birds that received sporocysts from 1 of the infected opossums developed tissue parasites. Meronts in the vascular endothelium of the lung venous capillaries and cysts in the skeletal and cardiac muscle cells were observed in histological sections stained with hematoxylin and eosin. The microscopic cysts, which were predominantly in the tongue and leg muscles, ranged from 65.3 to 118.1 µm in length and 14.0 to 29.4 µm in width and from 0.9 to 1.9 µm in thickness of the cystic wall. Sections examined by transmission electron microscopy revealed that the cyst wall contained numerous slender and jagged-shaped protrusions, each with a finger-like formation at the end. The morphology, especially of the cyst wall, and the morphometry of the tissue cysts indicate that the parasite is Sarcocystis lindsayi and, therefore, the opossum, D. aurita , is now considered a definitive host for this species in Brazil.