The effect of early infection with Echinostoma paraensei on the interaction of Schistosoma mansoni with Biomphalaria glabrata and Biomphalaria tenagophila

Infection caused by the trematode Echinostoma paraensei has been shown to interfere in the natural resistance to infection by Schistosoma mansoni. Biomphalaria glabrata is susceptible to infection, while Taim isolate Biomphalaria tenagophila is resistant to infection by S. mansoni. These two snail species were assessed for infection with E. paraensei two days after exposure to S. mansoni miracidia. The number of B. tenagophila and B. glabrata infected with E. paraensei was lower in co-infected group, suggesting an antagonistic relationship. B. glabrata showed an increase in its susceptibility to S. mansoni, whereas B. tenagophila maintained its refractoriness to S. mansoni infection. Weekly comparisons made between the E. paraensei cercariae released from B. tenagophila and B. glabrata mono-infected snails revealed no quantitative differences. In contrast, S. mansoni cercariae released were higher in the B. glabrata co-infected group. Mortality rates were significantly greater in both species pertaining to co-infected group and unexpected mortalities were also observed in B. tenagophila exposed only to S. mansoni miracidia. Our study revealed that the B. tenagophila Taim isolate is susceptible to E. paraensei infection, although infection did not alter its resistance to S. mansoni infection

Ultrastructure and Cytochemistry of the Tegument of Atriaster heterodus (Platyhelminthes: Monogenea)

The tegument of the polyopisthocotylean monogenean Atriaster heterodus Lebedev & Parukhin, 1969 was studied using transmission electron microscopy. The outer syncytial layer of the tegument is connected to the internal cell bodies by cytoplasmic extensions which interweave between the muscular fibres. The free surface of the syncytium has projections of the external membrane which are similar to microvilli. The undulating basal membrane, with numerous narrow elongate projections, is associated with the basal lamina situated between the syncytial and muscular layers. The cell bodies and syncytial layer of the tegument exhibit two types of vesicles, one with fibrous contents and one with electron-dense contents; these were analysed using two cytochemical tests, the E-PTA and alcian blue methods, used for the first time on monogeneans

Scanning Electron Microscopy of Lagochilascaris minor Leiper, 1909 (Nematoda: Ascarididae)

Lagochilascaris minor Leiper, 1909 is a parasitic nematode with its biological cycle still unknown, even though it was found in humans, domestic and silvatic animals. Adult worms, collected by surgical drainage from a human patient from the State of Pará, Brazil, were micrographed using a scanning electron microscope. Morphological aspects of males and females such as cephalic structures, caudal papillae and cuticular patterns were analyzed and compared with the previous descriptions adding new data for the identification of this species

Comparative study of four species of trichuris roederer, 1761 (nematoda, trichurinae) by scanning electron microscopy

A comparative morphological study of Trichuris travassosi, T. vulpis, T. discolor and T. suis was performed using scanning electron microscopy. Cuticular inflation associated with the bacillary band, vulva and male external genital appendages were analyzed. Qualitative and quantitative analyses of these structures were made for each species; they are of taxonomic value

Cytochemical Analysis of the Body Wall of the Flounder Parasite Procamallanus (Spirocamallanus) halitrophus (Nematoda: Camallanidae)

Submitted by Sandra Infurna ([email protected]) on 2017-01-16T13:39:18Z No. of bitstreams: 1 melissa4_cardenas_etal_IOC_2012.pdf: 1555369 bytes, checksum: 1f90db2dc3e0df66d7f84c210ff522b6 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-01-16T13:49:31Z (GMT) No. of bitstreams: 1 melissa4_cardenas_etal_IOC_2012.pdf: 1555369 bytes, checksum: 1f90db2dc3e0df66d7f84c210ff522b6 (MD5)Made available in DSpace on 2017-01-16T13:49:31Z (GMT). No. of bitstreams: 1 melissa4_cardenas_etal_IOC_2012.pdf: 1555369 bytes, checksum: 1f90db2dc3e0df66d7f84c210ff522b6 (MD5) Previous issue date: 2012Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Helmintos Parasitos de Peixes. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Laboratório de Biologia de Helmintos Otto Wucherer. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Campus Macaé. Grupo de Sistemática e Biologia Evolutiva (GSE), Pólo Barreto. Macaé, RJ, Brasil.Procamallanus (Spirocamallanus) halitrophus (Fusco and Overstreet, 1978) is an intestinal parasite of the flounders Syacium papillosum and Citharichthys macrops, both of which are native to waters off the coast of the state of Rio de Janeiro, Brazil. With transmission electron microscopy, we observed the body wall which is composed of the cuticle, hypodermis, and somatic musculature. The cuticle of P. (S.) halitrophus is composed of 5 layers: the epicuticle, cortical, median, fibrous, and basal layers. Underlying the cuticle is the hypodermis, a syncytium that contains mitochondria, glycogen granules, vesicles, inclusion bodies, and an endoplasmic reticulum. The region of hypodermal chords contains a nucleus in addition to the other organelles and there is a basal lamina surrounding each muscle cell. The use of imidazolebuffered osmium tetroxide solution revealed the presence of lipids in the epicuticle, the membrane that surrounds each muscle cell, the inclusion bodies, and the endoplasmic reticulum. The phosphotungstic-acid technique revealed basic proteins in the epicuticle and dense bodies. The use of periodic acid-thiosemicarbazide-silver proteinate for carbohydrate detection did not show any reaction products in the cuticle. However, glycogen particles were evident in the hypodermis and muscle cells

The Ultrastructure of the Gastrodermis and the Nutrition of the Gill Parasitic Atriaster heterodus Lebedev and Paruchin, 1969 (Platyhelminthes: Monogenea)

The gastrodermis of Atriaster heterodus Lebedev & Paruchin, 1969 (Polyopisthocotylea), a gill parasite from Diplodus argenteus (Valenciennes, 1830), is composed of "U"-shape hematin cells and a connecting syncytium, both having cytoplasmic lamellae. These cells show outgrowths and bent folds which were seen to enclose lumen material. The trapped material was then subjected to endocytosis. The nature of ingested food material was comparatively analyzed by cytochemical and histochemical tests. Blood residues were detected in the gut but tests for mucins were negative. No intact erythrocytes were observed in the gut lumen