Jeannie Nascimento dos Santos

Human Intraocular Filariasis Caused by Dirofilariasp. Nematode, Brazil

A case of human intraocular dirofilariasis is reported from northern Brazil. The nematode was morphologically and phylogenetically related to Dirofilaria immitis but distinct from reference sequences, including those of D. immitis infesting dogs in the same area. A zoonotic Dirofilaria species infesting wild mammals in Brazil and its implications are discussed.

Detection of dog filariasis in Marajo Island, Brazil by classical and molecular methods

Canine filariasis in domestic and wild dogs, foxes, and wolves is caused by several species of filarids. Although these filarial species inhabit different loci in the vertebrate definitive hosts, they generally release microfilariae into the bloodstream. Data about filarial infection in dogs in Brazil, especially on the Marajo Island, is scarce. For this reason, we conducted an analysis of 188 domestic dogs within two Marajo Island municipalities. The overall prevalence of microfilaremic was 32.45%; taken by blood smear and modified Knott’s method. No significant difference of positivity between male and female was observed (X2 Yates’s correction = 0.341; p = 0.559). Significant age–infection ratios were detected (X2 = 32.943; p < 0.0001). A high occult infection was detected (53.84%). PCR of rDNA and phylogenetic tree indicated that the microfilariae and adult worms found in domestic dogs from Marajo Island were Dirofilaria immitis.

Endemic angiostrongyliasis in the Brazilian Amazon: Natural parasitism of Angiostrongylus cantonensis in Rattus rattus and R. norvegicus, and sympatric giant African land snails, Achatina fulica

Angiostrongylus cantonensis, the rat lungworm, is one etiological agent of eosinophilic meningoencephalitis in humans. This zoonosis is frequently found in Asia and, more recently, in North America, Caribbean Island and northeastern of South America. Until now, research of A. cantonensis in southern, southeastern and northeastern regions of Brazil has been found natural infections only terrestrial and freshwater intermediate snail hosts (Achatina fulica, Sarasinula marginata, Subulina octona, Bradybaena similaris and Pomacea lineate). In this study, we examined the occurrence of helminthes in the synantropic rodents Rattus rattus and Rattus norvegicus in northern Brazil, focusing on the role of these species as vertebrate hosts of A. cantonensis and A. fulica as intermediate host have found natural. Thirty specimens of R. rattus and twelve of R. norvegicus were collected in the Guamá and Jurunas neighborhoods of the city of Belém, in the Brazilian state of Pará, of which almost 10% harbored adult worms in their pulmonary arteries. Sympatric A. fulica were found to be infected by L(3) larvae, which experimental infection confirmed to be A. cantonensis. Natural infection of snails and rodents with A. cantonensis was confirmed through morphological and morphometrical analyses of adults and larvae using light microscopy, scanning electron microscopy and molecular sequences of partial Cytochrome Oxidase subunit I. Phylogenetic analyses showed that A. cantonensis isolated from Pará, Brazil is similar to Japan isolate; once these specimens produced a single haplotype with high bootstrap support with Rio de Janeiro isolate. This study confirms that A. cantonensis is now endemic in northern Brazil, and that R. rattus and R. norvegicus act as natural definitive hosts, and A. fulica as the intermediate host of the parasite in this region.

Rhabdias paraensis sp. nov.: a parasite of the lungs of Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia

The nematode parasites of Rhinella marina include species of the genus Rhabdias (Rhabdiasidae: Rhabditoidea). The present study describes Rhabdias paraensis sp. nov., which parasitizes the lungs of R. marina in Brazilian Amazonia. Of the more than 70 known species of this genus, 18 are parasites of bufonids, of which, eight are Neotropical. The new species described here is similar to Rhabdias alabialis in the absence of lips is different by the presence of conspicuous cephalic papillae. We describe details of the four rows of pores, which are distributed equally along the whole of the length of the body and connected with hypodermal cells, using histology and scanning electron microscopy. Other histological aspects of the internal structure of this nematode are also described.

A New Species of Oswaldocruzia (Molineidae: Nematoda) in Chaunus marinus (Amphibian: Bufonidae) (Linneaus, 1758) from Brazil

Oswaldocruzia belenensis n. sp. (Strongylida: Molineidae) from the small intestine of Chaunus marinus (L.) from Belém, Pará State, Brazil is described and illustrated by light and scanning electron microscopy. Oswaldocruzia belenensis n. sp. is a neotropical species of this genus, harboring caudal bursa Type II, spicules divided in 3 branches, i.e., a blade, shoe, and fork. The blade is divided in 4 points, of which at least 2 are bifurcated. Cervical alae are absent; there is a simple cephalic vesicle and synlophe with low ridges perpendicular to the body without chitinous supports. The most closely related species are O. bonsi and O. lescurei. Oswaldocruzia belenensis n. sp. differs from O. lescurei and O. bonsi by the number and location of cephalic papillae, rays 2–3 and 5–6 running parallel and slightly separated, ray 6 not overlapping ray 8, and body structure morphometry. Oswaldocruzia belenensis n sp. also differs from O. lescurei by the discontinuity of the longitudinal ridges, the number of subdivisions of the blade, and the absence of extra processes at the bifurcation level of the fork of the spicules. The new species differs from O. bonsi by male and female body dimensions, the symmetry of the caudal bursa, dimension and subdivisions of the spicules without extra processes of the fork, 2 extra processes at the distal division of the blade, and location of ray 7 at the anterior margin of the cloacal aperture. Oswaldocruzia belenensis n. sp. represents the 82nd species assigned to the genus.

Calodium hepaticum (Nematoda: Capillariidae) in synanthropic rodents (Rattus norvegicus and Rattus rattus) in Eastern Amazonia

Calodium hepaticum (syn. Capillaria hepatica) is a trichurid nematode that parasitizes the hepatic parenchyma of rodents and other mammals. Infections in humans are rare, although they have been reported worldwide. A number of factors contribute to the distribution of this zoonosis, particularly the presence of dense populations of rodents associated with relatively poor urban environments, such as those found in parts of the northern Brazilian city of Belém in the eastern Amazon Basin. This study quantified Calodium infections in commensal synanthropic rodents in Belém. Rodents were captured in three neighborhoods characterized by poor public sanitation and the citys highest incidence of human leptospirosis. A total of 50 rodents were captured (26 Rattus rattus and 24 R. norvegicus), and 23 (10 R. rattus and 13 R. norvegicus) presented macroscopic lesions typical of C. hepaticum. Light microscopy of fresh samples and histological specimens permitted the identification of larvae and adult specimens containing numerous eggs with a double-striated shell and bipolar opercula with plugs. This is the first report of C. hepaticum in R. rattus and R. norvegicus from the Amazon Basin, and it shows a considerable risk of transmission to the local human population.

Liver Histopathology in the Cane Toad, Rhinella marina (Amphibia: Bufonidae), Induced by Ortleppascaris sp. Larvae (Nematoda: Ascarididae)

Abstract: Exposure to parasites is considered to be an important factor in the development of many diseases and histopathologies which are the result of the parasite–host interaction. The present study evaluated the impact of natural infection by larvae of Ortleppascaris sp. (Nematoda: Ascaridida) in the liver of the cane toad Rhinella marina (Linnaeus, 1758). Larvae were encysted in nodules delimited by collagenous fibers and fibroblasts or freely within the hepatic parenchyma, provoking a clear response from the host. The histological examination of the liver revealed viable larvae in a number of different developmental stages, as well as cysts filled with amorphous material and cell residues and surrounded by dense fibrotic tissue. The infection of the liver by these larvae induces a significant increase in the area occupied by melanomacrophages and a reduction or deficit in the vascularization of the liver, hypertrophy of the hepatocytes, vacuolar bodies, and cytoplasmatic granules. Focal concentrations of inflammatory infiltrates were observed enclosing the unencapsulated early-stage larvae. These results indicate that infection by Ortleppascaris sp. induces severe physiological problems and histopathological lesions in the liver of R. marina.

Morphological redescription of Dirofilaria immitis.

Abstract Morphological descriptions of Dirofilaria immitis are scarce. For this reason, we carried out morphological studies using both light and scanning electron microscopy for this filaroid species. Morphometric and morphological data were compatible with previous descriptions of D. immitis, but several anatomical structures are described by scanning electron microscopy for the first time, such as details of the cuticular striations, positioning of amphids, visualization of anal and vulvar opening, descriptions of deirids, lateral line, the pair of phasmids in the posterior end in females, and visualization of a small pair of latero-terminal papillae in the posterior end in males.

A NEW CUCULLANID SPECIES (NEMATODA) FROM AGENEIOSUS UCAYALENSIS CASTELNAU, 1855 (PISCES: AUCHENIPTERIDAE) FROM PARA ´ , BRAZIL

Abstract Cucullanus ageneiosus n. sp. (Nematoda: Cucullanidae) is described from the intestine of the Ageneiosus ucayalensis, from the Guajará Bay, Belém, Pará, Brazil. The new species is characterized mainly by arrangement of male caudal papillae, and the position of lateral phasmids immediately posterior of 10th papillae, markedly short and unequal spicules, a precloacal sucker, and the presence of an unpaired median papilla just of the anterior cloacal lip.

Lanfrediella amphicirrus gen. nov. sp. nov. Nematotaeniidae (Cestoda: Cyclophyllidea), a tapeworm parasite of Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae)

The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles, includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the difficulties of observing many anatomical traits. This study presents and describes a new genus and species of nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction. Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied using Historesin analysis, SEM and 3D reconstruction, and it is the second taxon for which molecular data have been deposited in GenBank.