Inter-relacionamento entre o tremat?deo digen?tico postharmostomum gallinum Witenberg, 1923 e o hospedeiro intermedi?rio Bradybaena similaris (F?russac, 1821)

• Autor(a) principal: Bezerra, Jos? Clecildo Barreto
• Data de Publicação: 1989
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/4084
• topic: Medicina Veterin?ria; Medicina Veterin?ria

The relationship between Postharmostomum gallinum and Bradybaena similaris was studied with the following objectives: a) to evaluate the prevalence and the intensity of infection in the snail host; b) to analyse if there was correlation between the intensity of infection and the size of the snail host; and c) to evaluate the alterations caused by the parasite in the intermediate host. The snails B. similaris were maintained in different types of terraria: plastic boxes, Petri dishes, wooden boxes, glass aquaria, acrylic boxes and cement boxes. In the cement boxes a small vegetal community was planted, and this type of terrarium showed to be the best for rearing the snails. To confirm the identification of the metacercaria found in B. similaris pericardial cavity, five days old Leghorn chick were experimentally infected. The trematodes collected from the ceca of these birds were identified as P. gallinum. A total of 7,103 B. similaris were collected from vegetable and flower gardens from Campo Grande suburb, Rio de Janeiro County and from the xxiv. Municipalities of Paracambi and Itagua?, State of Rio de Janeiro, Brazil, between October 1983 and September 1988. The prevalence of P. gallinum as metacercariae in B. similaris was calculated to be 33.3% among the 7,103 snails collected. A sample of 270 B. similaris, which had been previously identified as infected by examination through the snail shell, was dissected and the prevalence of P. gallinum as sporocysts was found to be 0.7%. The intensity of infection varied between 1 and 94 metacercariae per pericardial cavity. Correlation analysis showed no correlation between the number of metacercariae present in the pericardial cavity and the snail size. Also in this sample it was found a concurrent infection with metacercariae of P. gallinum in the pericardial cavity and mature sporocysts of Eurytrema coelomaticum in the digestive gland. Evaluation of the snails mortality in the laboratory made through the statistic's Table of Contingency indicated the mortality being related to the presence of metacercariae in the snails pericardial cavity. The presence of P. gallinum larvae in B. similaris caused alterations in the acinar cells of the digestive gland in the infected snails, when compared to non-infected ones, such as: the acinar cells had pycnotic nuclei, their outline could not be seen, there was an increase in cytoplasmic vacuoles and showed increased amount of secretions granules. The ovotestis of the infected snails showed smaller lobules than that of the non-infected, although histology showed that the gametogenesis was preserved in these snails. When metacercariae were present in the pericardial xxv. cavity, the lining of this cavity was thicker and villosities were present. Frequently it could be seen metacercariae with a light yellowish color. Histology showed the presence of an uniform layer covering the tegument of these metacercariae. Histochemical tests showed that this layer was not cellular and that it had an acid mucopolyssacharide composition