Giardia duodenalis: inter-strain variability of proteins, antigens, proteases, isoenzymes and nucleic acids

Os isolados de Giardia duodenalis de individuos assintomaticos, de pacientes e de animais apresentam diferencas e semelhancas em sua composicao proteica, expressao de antigenos, proteases e isoenzimas, assim como na constituicao dos acidos nucleicos. A presente revisao analisa estas diferencas com enfase na interacao parasita e hospedeiro, e nos possiveis mecanismos de virulencia do protozoario

Giardia agilis: ultrastructure of the trophozoites in the frog intestine

Intestine samples of Bufo sp. tadpoles with parasitism confirmed for Giardia agilis were studied by transmission electron microscopy. The G. agilis trophozoites were long and thin. The plasma membrane was sometimes undulated and the cytoplasm, adjacent to the dorsal and ventral regions, showed numerous vacuoles. The two nuclei presented prominent nucleoli. The cytoplasm was electron-dense with free ribosomes, glycogen and rough endoplasmic reticulum-like structures. Polyhedral inclusions were observed in the cytoplasm and outside the protozoan; some of these inclusions exhibited membrane disruption. The flagella ultrastructure is typical, with the caudal pair accompanied by the funis. Next to the anterior pair, osmiophilic material was noticed. The ventro-lateral flange was short and thick, supported by the marginal plates that penetrated into its distal extermity; only its distal portion had adjacent osmiophilic filament. The G. agilis trophozoites showed the general subcellular feature of the genus. However, the ventro-lateral flange ultrastructure was an intermediate type between G. muris and G. duodenalis.

Blastocystis hominis: occurrence in children and staff members of municipal day-care centers from Botucatu, Säo Paulo State, Brazil

To study the frequency of Blastocystis hominis among healthy individuals, feces were collected from 153 children and 20 staff members of some municipal day-care centers. Three separate stool specimens of each individual were processed by Lutz and Faust methods. From 173 studied individuals, 60 (34.7 per cent ) showed B. hominis, frequently in association with other intestinal parasites and/or commensals. B. hominis was found mainly in adults and children between 36 and 72 months old. All positive cases were detected only by Lutz method and the use of three stool specimens increased the positivity of the parasitological diagnostic

Giardia in dogs in Botucatu, Säo Paulo State, Brazil: a comparative study of canine and human species

Giardia sp foi encontrada em 30 (6,66%) de 450 cäes examinados. Devido à possível importância epidemiológica da infecçäo canina para o homen, cistos e trofozoitos originários de ambos os hospedeiros foram medidos, sendo as diferenças entre as médias de comprimento e largura testadas por análise de variância. Os resultados obtidos, näo significantes a nível de 0,05% permite-nos concluir näo haver diferenças de tamanho entre Giardia provenientes de homem e de cäo