RESUMO
Species in the genus Gorgoderina Looss, 1902 are parasites of the urinary bladder of amphibians and include around 50 species described globally. Molecular data on species of the genus are scarce, as is the information of their life-cycle patterns. During a survey on the genetic characterization of the frog trematodes in the tropical rain forest of Los Tuxtlas, in the Gulf of Mexico slope of Mexico, specimens of two morphotypes of Gorgoderina were sampled from the Rio Grande leopard frog, Rana berlandieri. One of them represented an undescribed species which is described herein as Gorgoderina rosamondae n. sp., whereas the other one was morphologically very similar to an apparently widely distributed North American species, G. attenuata, which has been previously reported in the same geographical area. Specimens of both morphotypes were sequenced for two nuclear and one mitochondrial genes. Phylogenetic trees corroborated the distinction of the new species, and data on the internal transcribed spacer 2 revealed genetic differences between G. attenuata sequenced from frogs in USA and specimens of Gorgoderina sp. from Los Tuxtlas, indicating the possibility that they also represent an undescribed species. COI sequences showed high genetic divergence values between the new species and Gorgoderina sp. from Los Tuxtlas (8.63-9.99%). Additionally, COI sequences of the larval forms (sporocyst, cercariae and metacercariae) sampled in the same locality from their first and second intermediate hosts (Pisidium sp. and Agriogomphus tumens, respectively) showed conspecificity, and the 3 host life-cycle of the new species was elucidated.
Assuntos
Ranidae , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Cercárias/anatomia & histologia , Cercárias/classificação , Cercárias/crescimento & desenvolvimento , Cercárias/ultraestrutura , Metacercárias/anatomia & histologia , Metacercárias/classificação , Metacercárias/crescimento & desenvolvimento , Metacercárias/ultraestrutura , México/epidemiologia , Microscopia Eletrônica de Varredura , Oocistos/classificação , Oocistos/citologia , Oocistos/crescimento & desenvolvimento , Oocistos/ultraestrutura , Filogenia , Prevalência , Trematódeos/anatomia & histologia , Trematódeos/crescimento & desenvolvimento , Trematódeos/ultraestrutura , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologiaRESUMO
INTRODUCTION: A new coccidian species of the genus Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae), is reported from the bat host Myotis riparius Handley from Ilha Grande, a large island off the coast of the State of Rio de Janeiro, in southeastern Brazil. METHODS: Bats were captured in 13 mist nets (10 × 3 m), which were set within the experimental plots, and through active searches of the daytime roosts of Molossus molossus Pallas found in Vila Dois Rios. Containment was made in bags for the collection of feces and identification of coccidia. A survey was conducted on the coccidia species described so far (Table 2). RESULTS: The oöcysts of Eimeria riparii n. sp. are ellipsoidal to cylindroidal with an extremely thin, bi-layered wall, slightly rough. Two polar granules are present, micropyle and oöcyst residuum are both absent. The sporocysts are ellipsoidal, the sporocyst residuum is formed by sparse, rounded granules of varying sizes; the Stieda body is trapezoidal and a sub-Stieda body is absent. Sporozoites are banana shaped. With the new species described here, a total of 40 Eimeria spp. have been described infecting bat hosts, belonging to 30 species of 18 genera and 5 families. CONCLUSION: The subsequent increase in the known diversity of bats has been derived from the ongoing expansion of research in a number of different areas of taxonomy and ecology although the number of studies of the associated coccidian parasites of the family Eimeriidae has increased more slowly.
Assuntos
Quirópteros/parasitologia , Coccidiose/veterinária , Eimeria/classificação , Animais , Brasil , Coccidiose/parasitologia , Eimeria/isolamento & purificação , Eimeria/ultraestrutura , Fezes/parasitologia , Florestas , Intestino Delgado/parasitologia , Intestino Delgado/patologia , Ilhas , Microscopia de Interferência , Oocistos/classificação , Oocistos/isolamento & purificação , Oocistos/ultraestruturaRESUMO
This work describes the detailed ultrastructural morphology of the phagocyte imprisoning an oyster of Nematopsis (Apicomplexa) found in Crassostrea rhizophorae, in the city of Maceió (AL), Brazil. The highly infected hosts had half-open leaflets with weak, slow retraction of the adductor muscles. Variable number of ellipsoid oocytes, either isolated and or clustered, was found between myofibrils of the adductor muscle. Each oocyst was incarcerated in a parasitophorous vacuole of host uninucleated phagocyte. The oocysts were composed of a dense wall containing a uninucleate vermiform sporozoite. The wall of the fine oocysts was composed of homogeneous electron-lucent material formed by three layers of equal thickness, having a circular orifice-micropyle obstructed by the operculum. The oocysts presented ellipsoid morphology with their wall was surrounded by a complex network of numerous microfibrils. Important details of the taxonomic value were visualized such as the ultrastructural organization of the oocyst wall and the organization of the micropyle and operculum, beyond the microfibrils that protrude from the oocyst wall only observed by transmission electron microscopy (TEM) and that may aid in the identification of the species. However, in order to clarify the systematic position of the species reported of the genus Nematopsis, it is important to proceed with genetic analyses.
Assuntos
Apicomplexa/ultraestrutura , Crassostrea/parasitologia , Oocistos/ultraestrutura , Fagócitos/ultraestrutura , Animais , Apicomplexa/isolamento & purificação , Brasil , Microscopia Eletrônica de TransmissãoRESUMO
Abstract This work describes the detailed ultrastructural morphology of the phagocyte imprisoning an oyster of Nematopsis (Apicomplexa) found in Crassostrea rhizophorae, in the city of Maceió (AL), Brazil. The highly infected hosts had half-open leaflets with weak, slow retraction of the adductor muscles. Variable number of ellipsoid oocytes, either isolated and or clustered, was found between myofibrils of the adductor muscle. Each oocyst was incarcerated in a parasitophorous vacuole of host uninucleated phagocyte. The oocysts were composed of a dense wall containing a uninucleate vermiform sporozoite. The wall of the fine oocysts was composed of homogeneous electron-lucent material formed by three layers of equal thickness, having a circular orifice-micropyle obstructed by the operculum. The oocysts presented ellipsoid morphology with their wall was surrounded by a complex network of numerous microfibrils. Important details of the taxonomic value were visualized such as the ultrastructural organization of the oocyst wall and the organization of the micropyle and operculum, beyond the microfibrils that protrude from the oocyst wall only observed by transmission electron microscopy (TEM) and that may aid in the identification of the species. However, in order to clarify the systematic position of the species reported of the genus Nematopsis, it is important to proceed with genetic analyses.
Resumo Este trabalho descreve a morfologia ultraestrutural detalhada do fagócito encarcerando um oocisto de Nematopsis (Apicomplexa) encontrado em Crassostrea rhizophorae, na cidade de Maceió (AL), Brasil. Os hospedeiros muito infectados apresentavam valvas entreabertas com retração fraca e lenta dos músculos abdutores. Número variável de oócitos de forma elipsoide, isolados e ou agrupados foi encontrado entre as miofibrilas do músculo abdutor. Cada oocisto estava encarcerado num vacúolo parasitóforo do fagócito uninucleado do hospedeiro. Os oocistos eram compostos por uma parede densa contendo um esporozoíto vermiforme uninucleado. A parede dos oocistos finos era composta de material electron-lucente homogêneo formado por três camadas de espessura igual, possuindo um orifício circular - micrópila, obstruída pelo opérculo. Os oocistos apresentavam morfologia elipsoide, sua parede era circundada por uma complexa rede de numerosas microfibrilas. Detalhes de valor taxonômico importantes foram visualizados tais como: a organização ultraestrutural da parede do oocisto e a organização da micrópila e do opérculo, além das microfibrilas que se projetam da parede do oocisto, estrutura apenas observada em microscopia eletrônica de transmissão (MET) e que pode auxiliar na identificação da espécie. Contudo, para esclarecer a posição sistemática da maioria das espécies relatadas do gênero Nematopsis é importante prosseguir com as análises genéticas.
Assuntos
Animais , Fagócitos/ultraestrutura , Apicomplexa/ultraestrutura , Oocistos/ultraestrutura , Crassostrea/parasitologia , Brasil , Apicomplexa/isolamento & purificação , Microscopia Eletrônica de TransmissãoRESUMO
A species of Isospora Schneider, 1881 (Protozoa: Apicomplexa: Eimeriidae) considered as new to science is described and characterised molecularly from the eastern white-throated spadebill Platyrinchus mystaceus Vieillot in the Parque Nacional do Itatiaia, southeastern Brazil. Isospora lopesi n. sp. has oöcysts that are subspheroidal to ovoidal, 18-24 × 18-22 (20.6 × 19.7) µm, with smooth, bilayered wall, c.1.5 µm thick. Micropyle and oöcyst residuum are absent, but one polar granule is present. Sporocysts are ellipsoidal, 12-16 × 8-11 (14.4 × 8.6) µm. The Stieda body is flattened to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, consisting of numerous spherules of different sizes. Sporozoites are vermiform with anterior and posterior refractile bodies and nucleus. Molecular analysis was conducted at the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This new isolate exhibited similarity greater than 98% with Isospora spp. isolates from spectacled warblers Sylvia conspicillata Temminck, 1820. This is the fourth isosporoid coccidian described from New World tyrannid birds, but is the first to have a complementary molecular characterisation.
Assuntos
Isospora/classificação , Passeriformes/parasitologia , Animais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Isospora/genética , Isospora/ultraestrutura , Oocistos/ultraestrutura , América do Sul , Especificidade da EspécieRESUMO
BACKGROUND: Malaria is transmitted when an infected mosquito delivers Plasmodium sporozoites into a vertebrate host. There are many species of Plasmodium and, in general, the infection is host-specific. For example, Plasmodium gallinaceum is an avian parasite, while Plasmodium berghei infects mice. These two parasites have been extensively used as experimental models of malaria transmission. Plasmodium falciparum and Plasmodium vivax are the most important agents of human malaria, a life-threatening disease of global importance. To complete their life cycle, Plasmodium parasites must traverse the mosquito midgut and form an oocyst that will divide continuously. Mature oocysts release thousands of sporozoites into the mosquito haemolymph that must reach the salivary gland to infect a new vertebrate host. The current understanding of the biology of oocyst formation and sporozoite release is mostly based on experimental infections with P. berghei, and the conclusions are generalized to other Plasmodium species that infect humans without further morphological analyses. RESULTS: Here, it is described the microanatomy of sporozoite escape from oocysts of four Plasmodium species: the two laboratory models, P. gallinaceum and P. berghei, and the two main species that cause malaria in humans, P. vivax and P. falciparum. It was found that sporozoites have species-specific mechanisms of escape from the oocyst. The two model species of Plasmodium had a common mechanism, in which the oocyst wall breaks down before sporozoites emerge. In contrast, P. vivax and P. falciparum sporozoites show a dynamic escape mechanism from the oocyst via polarized propulsion. CONCLUSIONS: This study demonstrated that Plasmodium species do not share a common mechanism of sporozoite escape, as previously thought, but show complex and species-specific mechanisms. In addition, the knowledge of this phenomenon in human Plasmodium can facilitate transmission-blocking studies and not those ones only based on the murine and avian models.
Assuntos
Oocistos/parasitologia , Oocistos/ultraestrutura , Plasmodium/fisiologia , Plasmodium/ultraestrutura , Esporozoítos/fisiologia , Esporozoítos/ultraestrutura , Animais , Aves , Feminino , Humanos , Estágios do Ciclo de Vida , Camundongos , Microscopia Eletrônica de VarreduraRESUMO
Five of 16 (31%) rufous-capped warblers (Basileuterus rufifrons) and 2 of 5 (40%) ovenbirds ( Seiurus aurocapilla ) sampled from Costa Rica were positive for a novel species of Isospora. Oocysts have a thin, smooth, double-layered, colorless wall and measure 22.3 µm ± 1.6 µm × 24.3 µm ± 1.5 µm (19-25 µm × 21-28 µm) with an average length-width (L/W) ratio of 1.0 (1-1.3). Oocyst residuum and micropyle are absent, but 0-4 spherical to cigar-shaped polar granules (1-2.5 µm) are present. Sporocysts are ovoid and measure 11.8 µm ± 0.9 µm × 16 µm ± 1.7 µm (10-14 µm × 12-19 µm) with an average L/W ratio of 1.6 (1.0-1.9). A knob-like Stieda body continuous with the sporocyst wall and a trapezoidal compartmentalized substieda body are present. Each sporocyst contained 4 sporozoites and a diffuse sporocyst residuum consisting of many variable-sized granules, some as large as 2 µm. This is the second description of an Isospora species in New World warblers (Passeriformes: Parulidae) and the first report of Isospora from both the rufous-capped warbler and ovenbird.
Assuntos
Doenças das Aves/parasitologia , Isospora/isolamento & purificação , Isosporíase/veterinária , Aves Canoras/parasitologia , Animais , Doenças das Aves/epidemiologia , Costa Rica/epidemiologia , Ecossistema , Isospora/classificação , Isospora/ultraestrutura , Isosporíase/epidemiologia , Isosporíase/parasitologia , Oocistos/ultraestrutura , PrevalênciaRESUMO
We elucidate the life cycle of Maritrema orensense for the first time and experimentally confirm that of the sympatric Maritrema bonaerense. In Argentinean estuaries, both species parasitize the cochliopid snail Heleobia australis as first intermediate host, the grapsid crabs Neohelice granulata and Cyrtograpsus angulatus as second intermediate hosts, and gulls as definitive hosts. Here, we describe the daughter sporocysts and cercariae of M. orensense and redescribe these stages for M. bonaerense. Sporocysts of M. orensense are shorter, with fewer developed cercariae than M. bonaerense. The cercariae of M. orensense have longer, larger, and more undulating cephalic glands than M. bonaerense. We redescribe metacercariae and adults of both species and compare them with the previous descriptions. Intestinal ceca length, vitellaria shape and extension, and egg size are the most relevant characteristics in metacercariae and adults for differentiating the species. Hence, the detailed morphological description and comparative analyses of morphometrics obtained from natural and experimental infections permit clear differentiation of M. orensense and M. bonaerense at each life stage.
Assuntos
Doenças das Aves/parasitologia , Braquiúros/parasitologia , Estágios do Ciclo de Vida , Caramujos/parasitologia , Trematódeos/crescimento & desenvolvimento , Infecções por Trematódeos/veterinária , Animais , Cercárias/crescimento & desenvolvimento , Cercárias/ultraestrutura , Charadriiformes/parasitologia , Galinhas , Análise Discriminante , Brânquias/parasitologia , Enteropatias Parasitárias/parasitologia , Enteropatias Parasitárias/veterinária , Intestinos/parasitologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Metacercárias/crescimento & desenvolvimento , Metacercárias/isolamento & purificação , Metacercárias/ultraestrutura , Microscopia Eletrônica de Varredura , Oocistos/crescimento & desenvolvimento , Oocistos/ultraestrutura , Trematódeos/anatomia & histologia , Trematódeos/classificação , Infecções por Trematódeos/parasitologiaRESUMO
Nine opossums, Didelphis aurita , were captured in the city of Seropédica, State of Rio de Janeiro, Brazil and examined for species of Sarcocystis. Sporocysts were observed in the mucosal scrapings of the small intestine from 3 opossums. Five budgerigars, Melopsittacus undulatus , were infected with sporocysts from each of these infected opossums and 5 budgerigars were used as controls. Of the 15 sporocyst-treated budgerigars, 5 birds that received sporocysts from 1 of the infected opossums developed tissue parasites. Meronts in the vascular endothelium of the lung venous capillaries and cysts in the skeletal and cardiac muscle cells were observed in histological sections stained with hematoxylin and eosin. The microscopic cysts, which were predominantly in the tongue and leg muscles, ranged from 65.3 to 118.1 µm in length and 14.0 to 29.4 µm in width and from 0.9 to 1.9 µm in thickness of the cystic wall. Sections examined by transmission electron microscopy revealed that the cyst wall contained numerous slender and jagged-shaped protrusions, each with a finger-like formation at the end. The morphology, especially of the cyst wall, and the morphometry of the tissue cysts indicate that the parasite is Sarcocystis lindsayi and, therefore, the opossum, D. aurita , is now considered a definitive host for this species in Brazil.
Assuntos
Doenças das Aves/parasitologia , Didelphis/parasitologia , Melopsittacus/parasitologia , Sarcocystis/fisiologia , Sarcocistose/veterinária , Animais , Brasil , Microscopia Eletrônica de Transmissão/veterinária , Músculos/parasitologia , Oocistos/classificação , Oocistos/ultraestrutura , Sarcocystis/classificação , Sarcocystis/isolamento & purificação , Sarcocystis/ultraestrutura , Sarcocistose/parasitologiaRESUMO
Sinantropic rodents, mainly of the genus Rattus and Mus , can be used as indicators of environmental contamination by Cryptosporidium oocysts, responsible for high rates of infection in humans and animals, and for economic losses and poor health of individuals. In this work, in order to measure the frequency of Cryptosporidium in rodents in the urban area of Umuarama, PR, fecal samples of these animals were collected and analyzed using the Kinyoun staining method to determine the absolute and relative frequency of the parasite. From 50 samples collected, 26 showed rounded reddish structures, with the presence of parasitic forms inside, compatible with oocysts of Cryptosporidium sp. Higher frequency (P-value <0.05) is found in Rattus, with no difference between sexes and origin of animals. The measurement of oocysts suggests the occurrence of zoonotic species Criptosporidium parvum.(AU)
Os roedores sinantrópicos, principalmente dos gêneros Rattus e Mus, podem servir como indicadores da contaminação ambiental por oocistos de Cryptosporidium, parasito celular obrigatório, responsável por elevadas taxas de infecção no ser humano, e animais, e por perdas econômicas, e na saúde dos indivíduos. Neste trabalho, verificou-se a frequência de Cryptosporidium em roedores na área urbana de Umuarama, PR. Para tanto, foram coletadas amostras fecais dos roedores, que foram analisadas pelo método de Kinyoun, determinando a frequência absoluta e relativa do parasito. Das 50 amostras coletadas, 26% apresentaram estruturas arredondadas, com presença de formas parasitárias em seu interior e coloração avermelhada, compatíveis com oocistos deCryptosporidium sp. Maior frequência (P>0.05) foi encontrada em Rattus sem diferença entre os sexos e a origem dos animais. A mensuração dos oocistos sugere a ocorrência da espécie zoonótica Criptosporidium parvum(AU)
Roedores sinantrópicos, principalmente del género Rattus y Mus, pueden servir como indicadores de contami- nación ambiental por ooquistes de Cryptosporidium, parásito celular obligatorio, responsable por altas tasas de infección en el ser humano y animales, y para la salud de las personas y pérdidas económicas. En este estudio se verificó la frecuencia de Cryptosporidium en roedores de la zona urbana de Umuarama, PR. Fueron recogidas muestras de heces de los roedores, que fueron analizadas por el método Kinyoun, determinándose la frecuencia absoluta y relativa del parásito. De las 50 muestras recolectadas, 26% presentaban estructuras redondeadas, con presencia de formas parasitarias en su interior y coloración rojiza, compatibles con ooquistes de Cryptosporidium sp. Mayor frecuencia (P<0.05) se encontró en Rattus, sin diferencia entre los sexos y el origen de los animales. La medición de los ooquistes sugiere la ocurrencia de la especie zoonótica Cryptosporidium parvum.(AU)
Assuntos
Animais , Criptosporidiose/patologia , Zoonoses/transmissão , Poluição Ambiental/análise , Roedores/classificação , Oocistos/ultraestruturaRESUMO
The digenetic trematode Eurytrema coelomaticum is a parasite of pancreatic ducts of ruminants. The ultrastructure of the mother and daughter sporocysts of E. coelomaticum was analyzed. The mother sporocyst was attached to the coelome of the intestine wall of intermediate snail host Bradybaena similaris, intimately adhered in some regions. It presents a highly folded tegument with granules and the body wall was composed by an outer syncitial layer, basal lamina, and circular and longitudinal muscle layer. Below was the cell body (cyton) with the nucleus. The daughter sporocysts obtained by dissection exhibited many granules and secretory vesicle in the outer layer indicating an intense secretory activity. The body wall presented the same layers of the mother sporocysts, but the outer syncitial layer invaginated and an amorphous layer was present between the syncitial and circular muscle layers. The protonephridial excretory system was viewed. The anterior and posterior end of the expelled sporocyst exhibit a degenerated structure, but biological activity still occurred in these regions. The swollen middle of the body was filled by a lamellar structure formed by degenerating membranes, but the excretory system was preserved. The endocyst wall was fibrilar and filled by cercariae and amorphous, membranous and secretory material inside it. These results were discussed.
Assuntos
Oocistos/ultraestrutura , Trematódeos/ultraestrutura , Animais , Larva/ultraestrutura , Caramujos/parasitologiaRESUMO
The Neotropical psittacine species Amazona aestiva, commonly known as the blue-fronted Amazon, is one of the most common and best-known psittacine birds kept as a pet worldwide. However, very little is known about the diseases or parasites of these birds. In this study, we describe a new species, Eimeria aestivae, associated with these parrots. The new species is characterized by: ovoid smooth oocysts (n â=â 60), 36.8 (33.2-41.5) × 23.7 (21.7-25.7) µm, length/width ratio â=â 1.55; polar granule present; ellipsoidal sporocysts (n â=â 25), 19.8 (17.5-21.6) × 9.3 (8.3-9.9) µm; Stieda, sub-Stieda body, and sporocyst residuum present. Sporozoites (n â=â 20), 2 per sporocyst, elongate and curved, 17.6 (15.8-19.2) × 3.8 (3.2-4.8) µm; each with 2 refractile bodies. The oocysts of the other 2 eimerian species described for Amazona are larger than those of the presented species, but they all seem to be closely related because of some similarities among them.
Assuntos
Amazona/parasitologia , Doenças das Aves/parasitologia , Coccidiose/veterinária , Eimeria/classificação , Animais , Brasil , Coccidiose/parasitologia , Eimeria/isolamento & purificação , Eimeria/ultraestrutura , Oocistos/ultraestrutura , Esporos de Protozoários/ultraestruturaRESUMO
In this study, we describe 2 new species of Eimeria associated with the yellow-crowned Amazon Amazona ochrocephala. Eimeria amazonae n. sp. has bilayered, ellipsoidal, and smooth oocysts that measure 48.9 × 36.2 µm; the length/width ratio is 1.35. The micropyle and oocyst residuum are both absent, but the polar granule is present. Ovoidal sporocysts are 22.2 × 11.9 µm. Stieda and sub-Stieda bodies and sporocyst residuum are present. The 2 elongate sporozoites are curved and measure 18.1 × 3.4 µm; both have 2 refractile bodies. Eimeria ochrocephalae n. sp. has bilayered, ellipsoidal, and smooth oocysts that measure 43.8 × 27.7 µm; the length/width ratio is 1.58. The micropyle and oocyst residuum are absent, but the polar granule is present; ovoidal sporocysts are 20.6 × 10.1 µm. Stieda and sub-Stieda bodies and sporocyst residuum are present; 2 elongate and curved sporozoites are 15.8 × 3.4 µm, each of which has 2 refractile bodies.
Assuntos
Amazona/parasitologia , Doenças das Aves/parasitologia , Coccidiose/veterinária , Eimeria/classificação , Animais , Coccidiose/parasitologia , Eimeria/ultraestrutura , Oocistos/ultraestrutura , Esporos de Protozoários/ultraestrutura , Esporozoítos/ultraestruturaRESUMO
Eurytrema coelomaticum is a fluke that infects ruminants in South America, Europe and Asia. The morphology of the mother and daughter sporocysts of E. coelomaticum obtained from Bradybaena similaris, the first intermediate host, is described for the first time by light and scanning electron microscopy. The intermediate host was exposed to E. coelomaticum eggs and after 30 days the mother sporocyst was found in the coelom adhered to the intestine wall. This sporocyst was a rounded or elongated mass (0.1078 mm), with numerous germinal balls in it, and a folded tegument with no specializations. The daughter sporocysts obtained following dissection of infected snails have varied shape, one hollow tapered region with many transversal and longitudinal striations, named anterior end. The expelled daughter sporocyst presented an oval sac-like central region with a small anterior and a posterior longer filament-like prolongation. The measures of the expelled sporocysts are presented and compared to previous descriptions.
Assuntos
Microscopia Eletrônica de Varredura , Oocistos/ultraestrutura , Caramujos/parasitologia , Trematódeos/ultraestrutura , AnimaisRESUMO
Two (33.3%) of 6 blue-crowned motmots (Momotus momota) sampled from Costa Rica were positive for a new species of Isospora. Oocysts of Isospora momotana n. sp. have a double, thick, yellow to orange, 2.3 microm +/- 0.5 microm (2-3 microm) wall, contain 1 to 3 globular polar granules (1-4 microm), are ovoid with heavy pitting on the outer surface, and measure 29.4 +/- 2.3 x 27.5 +/- 2.3 (25-33 x 23-31) with an average length:width ratio of 1.1 (1.0-1.35). Sporocysts are ovoid, contain a residuum composed of large, equal-sized granules, and measure 19.4 +/- 1.3 x 12.2 +/- 1.1 (16-22 x 10-14) with an average length:width ratio of 1.6 (1.2-1.91). A small rounded stieda body, continuous with the sporocyst wall, and a prominent triangular substieda body are present. A second Isospora species was observed in 1 bird, but because only a few oocysts were present, a full description is not provided. This is the first report of coccidia from a motmot (Momotidae) and only the third Ispospora species described from the Coraciiformes.
Assuntos
Doenças das Aves/parasitologia , Isospora/classificação , Isosporíase/veterinária , Animais , Doenças das Aves/epidemiologia , Aves , Costa Rica/epidemiologia , Fezes/parasitologia , Isospora/ultraestrutura , Isosporíase/epidemiologia , Isosporíase/parasitologia , Oocistos/ultraestrutura , PrevalênciaRESUMO
Este estudo objetivou avahar a ocorrência de oocistos de Cryptosporidium spp. em emas (Rhea americana) cativas no Parque Zoológico da Fundação Zoobotânica do Rio Grande do Sul, sul do Brasil. Foram identificados oocistos de Cryptosporidium spp. em esfregaços de fezes de emas e em amostras de agua, coradas pela técnica de Ziehl-Neelsen modificada. A análise morfométrica dos coccídeos revelou pequenos oocistos esféricos medindo, em media, 4,91 um X 4,91 /im e relação comprimento/largura de razão 1. A confirmação da prêsera de oocistos nas amostras de fezes e de agua é relevante pelo potencial de transmissão e manutenção da criptosporidiose em hospedeiros susceptíveis. Este é o primeiro relato de Cryptosporidium spp. em R. americana no Brasil.
The aim of this study was to evaluate the occurrence of Cryptosporidium spp. oocysts in common rhea (Rhea americana) living in captivity in the zoological park of the Zoobotanical Foundation of the State of Rio Grande do Sul, southern Brazil. Cryptosporidium spp. oocysts were detected in fecal smears of common rhea and in water samples by using the modified Ziehl-Neelsen staining method. The morphometric analysis of coccidia revealed small spherical oocysts, measuring, on average, 4.91 [im x 4.91 fim, and a length/width ratio of 1. The detection of Cryptosporidium spp. oocysts in fecal and water samples is important as it can indicate the transmission and maintenance of cryptosporidiosis in susceptible hosts. This is the first report of Cryptosporidium spp. in R. americana in Brazil.
Assuntos
Animais , Criptosporidiose/epidemiologia , Cryptosporidium/isolamento & purificação , Fezes/parasitologia , Reiformes/parasitologia , Água/parasitologia , Animais de Zoológico/parasitologia , Brasil/epidemiologia , Oocistos/ultraestruturaRESUMO
Members of the genus Cryptosporidium in the phylum Apicomplexa were long thought to be closely related to the coccidia. However, despite strong morphological similarities to these organisms, Cryptosporidium has notable differences with them and similarities with the gregarine protozoa. On the basis of phylogenetic analysis of molecular data, some authors place Cryptosporidium at the basis of the phylum Apicomplexa, others consider species of this genus to be phylogenetically too distant from the coccidia and do not include them in this group of protozoa, and others think that Cryptosporidium is closely related to gregarines. The taxonomy of this genus and the naming of species are undergoing rapid change due to the new and increasing molecular information. Molecular characterization of oocysts using polymerase chain reaction based procedures has not only a major impact on resolving the taxonomy of Cryptosporidium at the species level but also on the molecular epidemiology of cryptosporidiosis. Today, it is recognized that this genus is a phenotypically and genotypically heterogeneous assemblage of largely morphologically identical species and genotypes. Fourteen Cryptosporidium species and 21 C. parvum genotypes are currently recognized. Phylogenetic analyses have shown that genetically related hosts often have related forms of Cryptosporidium. Application of molecular techniques to taxonomy and epidemiology is helping to characterize new and existing species and determine the sources of the parasites that will facilitate the identification of sources of water-borne cryptosporidiosis.
Assuntos
Cryptosporidium/classificação , Animais , Apicomplexa/classificação , Coccídios/classificação , Cryptosporidium/genética , Cryptosporidium/crescimento & desenvolvimento , DNA de Protozoário/genética , Humanos , Estágios do Ciclo de Vida , Oocistos/ultraestrutura , Filogenia , Especificidade da EspécieRESUMO
Schistosoma mansoni eggs, miracidia and primary sporocysts were labelled with phalloidin-rhodamine to visualize filamentous actin structures. Analysis of these forms by confocal fluorescence microscopy revealed the presence of previously well-defined circular and longitudinal muscle layers. Besides these muscular layers that sustain and provide motility to these parasite forms, we found in these 3 consecutive developmental stages of the parasite previously unidentified actin-rich tubular structures. In the 3 forms, 4 actin-rich tubules could be observed by optical sectioning underneath the well-developed muscle layers. The tubules appear in pairs, transversal to the length of the parasite, and located towards the extremities. By using an anti-flame cell specific antibody we confirmed that the tubules co-localize with flame cells and also determined that the tubule core is filled with microtubules. The additional presence of myosin in these tubules strongly suggests that they are contractile structures.
Assuntos
Estágios do Ciclo de Vida/fisiologia , Proteínas Motores Moleculares/análise , Schistosoma mansoni/química , Schistosoma mansoni/ultraestrutura , Citoesqueleto de Actina/imunologia , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestrutura , Actinas/análise , Actinas/imunologia , Animais , Anticorpos Anti-Helmínticos/metabolismo , Microscopia Confocal/métodos , Proteínas Motores Moleculares/imunologia , Músculos/química , Músculos/ultraestrutura , Miosinas/imunologia , Miosinas/metabolismo , Oocistos/ultraestrutura , Schistosoma mansoni/crescimento & desenvolvimentoRESUMO
In August of 2000, a comparative susceptibility study was conducted using 3 species of Anopheles mosquitoes from Belize, Central America, and a standard species used in laboratory infection studies, Anopheles stephensi. Test populations were fed human blood infected with cultured Plasmodium falciparum (NF-54 strain) parasites via a membrane feeder. The control species, An. stephensi, exhibited the highest infections, with 73.8% of dissected specimens positive for sporozoites in the salivary glands. The control species also showed heavier sporozoite loads; 74.0% of positive glands having greater than 200 sporozoites. Of species from Belize, Anopheles darlingi was the most susceptibile, e.g., 41.0% of salivary glands were positive, with more than 200 sporozoites per gland. Anopheles vestitipennis had a low salivary gland infection rate (9.3%) and a moderate number of sporozoites in glands (i.e., 85.7% containing 50-250 sporozoites). Anopheles albimanus was the least susceptible species to infection. No specimens of An. albimanus from the Golden Stream population developed sporozoites in the salivary glands, yet 20.7% of dissected specimens had positive midgut infections. The An. albimanus Buena Vista population showed similar results with only a 2.2% salivary gland infection rate and a 21.5% midgut infection rate. Oocysts in An. stephensi increased in size by 20% after day 10. Development peaked at day 12, with a mean oocyst diameter of 58 microm at onset of oocyst differentiation. Oocysts developed more slowly in An. vestitipennis until day 10. After day 10, there was a 53% increase in oocyst development over the previous 10 days. Oocyst differentiation was not observed until day 13 postfeed. As with An. vestitipennis, both populations of An. albimanus showed similar slow rates of oocyst development; however, no dramatic growth increase occurred after day 10. The oocysts in the Golden Stream population exhibited a cessation of growth after day 10, peaking at a mean of 30 microm. The Buena Vista population did not exhibit the same level of reduced oocyst development. A gradual increase in growth continued until days 13 and 14 (36.7 and 35.7 microm, respectively).
Assuntos
Anopheles/parasitologia , Plasmodium falciparum/fisiologia , Animais , Belize , Insetos Vetores/parasitologia , Malária Falciparum/transmissão , Oocistos/ultraestrutura , Glândulas Salivares/parasitologiaRESUMO
Oocysts of an unidentified coccidian are reported in this study to parasitize the gills of the oyster Crassostrea rizophorae (Mollusca, Bivalvia) collected near the city of Recife (Itamaracá Island, 07 degrees 38' 00" S, 34 degrees 48' 06" W), Brazil. Oocysts appeared as light and dense forms, both containing rod-shaped, bacteria-like hyperparasites (BL). Both light and dense oocysts were spherical, 4.3 to 4.7 pm in diameter, but denser oocysts had irregular contours. Both forms consisted of a thick dense wall (approximately 165 nm thick) consisting of 3 layers. The outermost, a dense and irregular layer about 25 nm thick, possessed numerous bead-like structures and some slender conical projections (up to 1.5 microm long). The inner layer of the wall was formed by a dense and homogenous layer about 125 nm thick. Between these 2 layers, a thin light layer about 12 nm thick was present. Uninucleated sporocysts occupied the internal space of the oocyst and contained some rod-shaped BL and mitochondria surrounded by numerous ribosome-like particles. The dense forms of the oocysts showed the same structures described in the lighter forms and appeared to be the final maturation form of the oocysts. Free sporozoites were occasionally observed among oocysts.