Delir Corrêa Gomes

Nematóides do Brasil. Parte V: nematóides de mamíferos

A survey of nematode species parasitizing Brazilian mammals is presented, with enough data to provide their specific identification. The tirst section refers to the survey ofthe species, related to 21 superfamilies, 45 families, 160 genera and 495 species that are illustrated and measurement tables are given. The second section is concerned to the catalogue ofhost mammals which includes 34 families, 176 species and their respective parasite nematodes. The identification of these helminths is achieved by means of keys to the superfamilies, families and genera. Specific determination is induced through the figures and tables as above mentioned.

Nematóides do Brasil. Parte IV: nematóides de aves

A survey of nematode species parasitizing Brazilian birds is presented, with enough data to provide their specific identification. The first section refers to the survey of the species, related to 17 superfamilies, 23 families, 75 genera and 257 species that are illustrated and measurement tables are given. The second section is concerned to the catalogue of host birds which includes 54 families. 361 species. and their respective parasite nematodes. The identification of these helminths is achieved by means of keys to the superfamilies. families and genera. Specific determination is induced through the figures and tables as above mentioned.

Nematóides do Brasil. Parte III: nematóides de répteis

A survey of nematode species parasizing Brazilian reptiles is presented, with data enough to provide their specific identification. The first section refers to the catalogation of the species, related to 127 superfamilies, 23 families, 55 genera and 121 species that are figured and included in measurement tables. The second section is concerned to the catalogue of host reptiles, with 16 families, and 90 species and their respective parasite nematodes. The identification of these helminths is achieved by means of keys to the superfamilies, families and genera. Specific determination is induced through the figures and tables as above mentioned.

A new description of the reproductive system of Schistosoma mansoni (Trematoda: Schistosomatidae) analyzed by confocal laser scanning microscopy

Classical schemes of the adult Schistosoma mansoni reproductive system have been described. In our study, whole adult worms derived from unisexual or mixed infections and stained with carmine chlorine were virtually and tomographically analyzed under confocal laser scanning microscopy. We found that: (1) there were morphological differences in the ovary, vitteline glands and testicular lobes between specimens derived from unisexual or mixed infections; (2) there was always a single lobed ovary (three or four lobes), presenting differentiation from the anterior to the posterior lobes, where the most mature oocytes were located; (3) the proximal segment of oviduct was connected to an ampullary dilatation, full of tailed spermatozoa, characterizing a seminal receptacle; (4) there was no long vitelline duct, but a short one that begins at the end of the proximal region of the vitelline gland; (5) long cells of Mehlis’ gland placed radially around the ootype were not observed. Otherwise, the ootype was only lined by thick cuboidal epithelial cells with plaited bases and nuclei with flabby chromatin, making a clear distinction from the uterine epithelium. This morphological feature suggests that each cell represents a gland. (6) In coupled males, the specimens located inside the gynaecophoric canal had smaller testicular lobes, suckers, and body length and width when compared to their partners. Our results show that the reproductive system does not follow a unique pattern within flatworms. Due to its better resolution, confocal laser scanning microscopy, using a reflected mode with tomographic sections, allows new interpretations, modifying the adopted and current descriptions of the internal morphological structures of S. mansoni adult worms.

Helminth parasites of conventionally mantained laboratory mice

The spectrum of intestinal parasites present in the Swiss Webster, C57B1/6 and DBA/2 mice strains from different animal houses was identified and prevalences compared. Three parasites were observed during the course of this study, namely the cestode Vampirolepis nana (Siebold, 1852) Spasskii, 1954 (= Hymenolepis nana) and the nematodes Aspiculuris tetraptera (Nitzsch, 1821) Schultz, 1924 and Syphacia obvelata (Rudolphi, 1802) Seurat, 1916. The scope of this investigation has been widened to also include morphometric data on the parasites, to further simplify their identification, since the presence of helminths in laboratory animals is regarded as a restricting factor for the proper attainment of experimental protocols.

Morphological study of adult male worms of Schistosoma mansoni Sambon, 1907 by confocal laser scanning microscopy

Aiming to detail data obtained through brightfield microscopy (BM) on reproductive, excretory and digestive system, specimens of Schistosoma mansoni eight weeks old, were recovered from SW mice, stained with Langerons carmine and analyzed under a confocal laser scanning microscope CLSM 410 (Carl Zeiss). The reproductive system presented a single and lobate testis, with intercommunications between the lobes without efferent duct. Supernumerary testicular lobe was amorphous and isolated from the normal ones. Collecting tubules (excretory ducts), followed by the excretory bladder, opening to the external media through the excretory pore, were observed at the posterior extremity of the body. In the digestive tract, a cecal swelling was noted at the junction that originates the single cecum. It was concluded that through confocal laser scanning microscopy, new interpretations of morphological structures of S. mansoni worms could be achieved, modifying adopted and current descriptions. The gonad consists of a single lobed testis, similar to that observed in some trematode species. Moreover, the same specimens can be observed either by BM or CLSM, considering that the latter causes only focal and limited damage in tissue structures.

Nematóides do Brasil 2ª parte: nematóides de anfíbios

Sao reunidas neste trabalho todas as especies de nematoides parasitas de anfibios encontradas no Brasil, com dados suficientes para a sua identificacao especifica. Na primeira parte que e o catalogo dos nematoides parasitos de anfibios, sao relacionadas nove superfamilias, quatorze familias, vinte e quatro generos e sessenta e tres especies, sendo que destas, sao dadas figuras e medidas. Na segunda parte que e o catalogo dos anfibios hospedeiros, todos pertencentes a ordem Anura, sao referidas seis familias e cinquenta e cinco especies de anfibios, estas com os nematoides respectivos. A identificacao dos nematoides e auxiliada por chaves de determinacao das superfamilias, familias e generos, sendo a identificacao especifica feita atraves de quadros de medidas e figuras.

Host-induced morphological changes of Schistosoma mansoni Sambon, 1907 male worms

In order to evaluate the permissiveness of Nectomys squamipes to Schistosoma mansoni and the influence of the albino mice on the morphological aspects of adult worms derived from a population isolated from N. squamipes, the morphology of adult S. mansoni Sambon, 1907 male worms was studied using a digital image analyser (MOP VIDEOPLAN) and light microscopy. Their sources were as follows: (1) recovered from the wild rodent N. squamipes Brants naturally infected from Sumidouro, RJ, Brazil; (2) recovered from albino mice experimentally infected with the strain derived from N. squamipes; (3) recovered after the isolation of a strain derived from aboriginal human infections in Sumidouro. Worms recovered from N. squamipes (group 1) showed body length and distance between suckers significantly bigger than those of the specimens maintained in mice (groups 2 and 3). The number of testes in group 1 was statistically less than that of groups 2 and 3. Group 2 strains which were maintained in mice, presented the length of the worms as the only significant different character. Data show that: (1) N. squamipes is a more suitable host for the development of S. mansoni when compared to the albino mice; (2) a strain of S. mansoni isolated from a natural host undergoes morphological changes after its passage in the white mouse.

Genetic and morphological characterisation of a new species of the genus Hysterothylacium (Nematoda) from Paralichthys isosceles Jordan, 1890 (Pisces: Teleostei) of the Neotropical Region, state of Rio de Janeiro, Brazil

Taking into account the difficulties of taxonomic identification of larval anisakid nematodes based on morphological characters, genetic analyses were performed, together with those usually applied, in order to identify anisakid larvae found in the flounder Paralichthys isosceles from the littoral of the state of Rio de Janeiro, Brazil. The analysis of 1,820 larvae revealed a new species, similar to Hysterothylacium MD, Hysterothylacium 2, Hysterothylacium KB and Hysterothylacium sp regarding the absence of the larval tooth, an excretory pore situated below the nerve ring level, and slender lateral alae. Moreover, the new species differs from Hysterothylacium fortalezae and Hysterothylacium reliquens with regard to the number and size of spines present on the tail end and from Hysterothylacium patagonicus by the absence of interlabia. The maximum parsimony and neighbour joining tree topologies based on the 18S ribosomal DNA gene, complete internal transcribed spacer region and cytochrome oxidase 2 (COII) gene demonstrated that the Brazilian larvae belong to Raphidascarididae and represent a unique genetic entity, confirmed as a new Hysterothylacium species. Furthermore, the new species presents COII genetic signatures and shares polymorphisms with Raphidascarididae members. This is the first description of a new anisakid species from Brazil through the integration of morphological and molecular taxonomy data.

Schistosoma mansoni Sambon, 1907: morphometric differences between adult worms from sympatric rodent and human isolates

A computer software for image analysis (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms, aiming the morphological characterization of Schistosoma mansoni samples isolated from a slyvatic rodent, Nectomys squamipes, and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for maless testicular lobes were analyzed: number, area, density, larger and smaller diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p < 0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p < 0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.