39 research outputs found
Paracoccidioidomicose enzoótica em tatus (Dasypus novemcinctus) no estado do Pará
Paracoccidioides brasiliensis foi encontrado, por inoculação de triturado de fígado e baço em hamsters, em 4 de 20 tatus (Dasypus novemcinctus) examinados na região de Tucuruí, Pará. Hamsters inoculados por via intradérmica e peritoneal com o parasito desenvolveram infecções generalizadas e morreram em 1½ a 13 meses. A diagnose do fungo foi confirmada por histopatologia e cultura. Não se observaram sinais macroscópios de doenças nos tatus. A distribuição geográfica de D. novemcinctus abrange a área endêmica de paracoccidioidomicose humana, sugerindo-se que o tatu tenha algum papel na ecologia do fungo.In spite of an extensive literature on paracoccidioidomycosis, hardly anything is known about the ecology of Paracoccidioides brasiliensis in nature. During 1983, 152 wild animals of 21 species "were examined in a survey designed to detect sylvatic hosts of Leishmania near Tucuruí, a region of tropical rainforest with acid soils, in the State of Pará, northern Brazil. Hamsters inoculated with saline suspensions of liver and spleen from 4 out of 20 Dasypus novemcinctus developed generalized systemic infections after 4 to 13 months, with abundant spherical parasitic structures up to 30 mm indiameter, visible in unstained tissue smears. Inoculation of this material into fresh hamsters, produced lethal infections in within 1½ to 5 months, with gross pathological changes in the viscera and abundant parasites characteristic of P. brasiliensis in stained histological sections. Material from infected tissue grew slowly in Sabouraud Dextrose Agar, forming light-coloured cerebriform colonies approximately 1,5 cm in diameter after 2 months at 22-26ºC. Culture material was inoculated intradermally, intraperitoneally and intratesticularly into hamsters, laboratory mice and guinea pigs. Generalized infections were detected after approximately 5 months in female hamsters that had been inoculated intradermally. The fungus was re-isolated in culture from the infected hamsters. Parasites were detected in histological sections of the liver and spleen of the original armadillos, but no gross signs of disease. were noted in these animals. D. novemcinctus is widely distributed in the Neotropical Region but is absent from certain regions, such as Chile and Patagonia, where paracoccidioidomycosis is unknown. The fossorial habits of this armadillo may be relevant in the light of previous suggestions that the saprophytic phase of P. brasiliensis inhabits a subterranean environment. It is suggested that D. novemcinctus may play a part in the ecology of P. brasiliensis in nature
Species diversity and flagellate infections in the sand fly fauna near Porto Grande, State of Amapá, Brazil (Diptera: Psychodidae. Kinetoplastida: Trypanosomatidae)
Forty-six species of Lutzomyia and one species of Brumptomyia were identified among 20,008 sand flies collected in central Amapá. L. squamiventris maripaensis, L. infraspinosa, L. umbratilis and L. ubiquitalis accounted for 66% of the specimens caught in light traps, and L. umbratilis was the commonest of the 16 species found on tree bases. Seven species of Lutzomyia including L. umbratilis were collected in a plantation of Caribbean pine. Sixty out of 511 female sand flies dissected were positive for flagellates. Among the sand flies from which Leishmania was isolated, promastigotes were observed in the salivary glands and foregut of 13 out of 21 females scored as having very heavy infections in the remainder of the gut, reinforcing the idea that salivary gland invasion may be part of the normal life cycle of Leishmania in nature. Salivary gland infections were detected in specimens of L. umbratilis, L. whitmani and L. spathotrichia. Parasites isolated from L. umbratilis, L. whitmani and also from one specimen of L. dendrophyla containing the remains of a bloodmeal, were compatible with Le. guyanensis by morphology and behaviour in hamsters
Paracoccidioidomicose enzoótica em tatus (Dasypus novemcinctus) no estado do Pará
Paracoccidioides brasiliensis foi encontrado, por inoculação de triturado de fígado e baço em hamsters, em 4 de 20 tatus (Dasypus novemcinctus) examinados na região de Tucuruí, Pará. Hamsters inoculados por via intradérmica e peritoneal com o parasito desenvolveram infecções generalizadas e morreram em 1½ a 13 meses. A diagnose do fungo foi confirmada por histopatologia e cultura. Não se observaram sinais macroscópios de doenças nos tatus. A distribuição geográfica de D. novemcinctus abrange a área endêmica de paracoccidioidomicose humana, sugerindo-se que o tatu tenha algum papel na ecologia do fungo
Development of Hepatozoon caimani (Carini, 1909) Pessôa, De Biasi & De Souza, 1972 in the Caiman Caiman c. crocodilus, the Frog Rana catesbeiana and the Mosquito Culex fatigans
The sporogony of Hepatozoon caimani has been studied, by light microscopy, in the mosquito Culex fatigans fed on specimens of the caiman Caiman c. crocodilus showing gametocytes in their peripheral blood. Sporonts iniciate development in the space between the epithelium of the insect gut and the elastic membrane covering the haemocoele surface of the stomach. Sporulating oocysts are clustered on the gut, still invested by the gut surface membrane. Fully mature oocysts were first seen 21 days after the blood-meal. No sporogonic stages were found in some unidentified leeches fed on an infected caiman, up to 30 days following the blood-meal. When mosquitoes containing mature oocysts were fed to frogs (Leptodactylus fuscus and Rana catesbeiana), cysts containing cystozoites developed in the internal organs, principally the liver. Feeding these frogs to farm-bred caimans resulted in the appearance of gametocytes in their peripheral blood at some time between 59 and 79 days later, and the development of tissue cysts in the liver, spleen, lungs and kidneys. Transmission of the parasite was also obtained by feeding young caimans with infected mosquitoes and it is suggested that both methods occur in nature. The finding of similar cysts containing cystozoites in the semi-aquatic lizard Neusticurus bicarinatus, experimentally fed with infected C. fatigans, suggests that other secondary hosts may be involved