RESUMEN
Raillietina celebensis is a cestode that parasitizes the small intestine of rats and humans. Here, we detail the morphology and morphometry of R. celebensis based on specimens collected from Rattus norvegicus in the municipality of São Gonçalo, state of Rio de Janeiro, Brazil, by light and confocal scanning laser microscopies and also report the results of molecular phylogenetic analyses to determine its relationships within the family Davaineidae. Analysis of the number and size of testes, number and shape of rostellar hooks, cirrus sac length, capsules and eggs per capsule, and morphology of the mature proglottid allowed concluding that the present specimens constitute a new record of R. celebensis in South America. Our genetic and phylogenetic analyses, based on the partial small subunit 18S rRNA gene, revealed R. celebensis to be in the family Davaineidae within the genus Raillietina, in agreement with the morphological taxonomy. Phylogenetic trees obtained by neighbor-joining and maximum likelihood methods demonstrated R. celebensis as a unique taxonomic unit, and also demonstrated some taxonomic inconsistences. The incorporation of Brazilian R. celebensis sequences derived from mammals in the phylogeny of davaineids is consistent with the assertion that neither Raillietina nor Fuhrmannetta can be supported as distinct genera.
Asunto(s)
Cestodos/clasificación , Infecciones por Cestodos/veterinaria , Enfermedades de los Roedores/parasitología , Animales , Brasil , Cestodos/anatomía & histología , Cestodos/genética , Infecciones por Cestodos/epidemiología , Infecciones por Cestodos/parasitología , Análisis por Conglomerados , ADN Ribosómico/química , Intestino Delgado/parasitología , Microscopía Confocal/veterinaria , Filogenia , Prevalencia , ARN Ribosómico 18S/genética , Ratas , Enfermedades de los Roedores/epidemiología , Población UrbanaRESUMEN
The complete life cycle of the trematode Ascocotyle (Phagicola) longa (Digenea: Heterophyidae) is elucidated by natural observation validated by experimental infections. The natural first intermediate host of A. (P.) longa, an agent of human heterophyiasis in Brazil, is the cochliopid snail Heleobia australis (new first intermediate host). Metacercariae were found encysted in the body musculature, heart, stomach, liver, kidney, spleen, gonads and mesentery of mullets Mugil liza. Hamsters Mesocricetus auratus were experimentally infected with metacercariae of A. (P.) longa obtained from the mullets, and the adults recovered were used to infect the snails H. australis. Rediae and cercariae of A. (P.) longa are described for the first time. The ultrastructure of the tegument of A. (P.) longa shows a change in spination pattern from the cercaria with single-pointed spines to the metacercaria and adult with multipointed, brush-shaped spines. The life cycle of A. (P.) longa is related to estuaries and coastal lagoons where the recruitment of mugilid juveniles occurs. The high prevalence (100%) of A. (P.) longa encysted in the mullets examined within the urban area of Rio de Janeiro indicates the potentially great public health impact of the consumption of raw mullets.
Asunto(s)
Heterophyidae/crecimiento & desarrollo , Estadios del Ciclo de Vida , Estructuras Animales/parasitología , Animales , Brasil , Cricetinae , Enfermedades Transmitidas por los Alimentos/parasitología , Heterophyidae/ultraestructura , Humanos , Mesocricetus/parasitología , Microscopía , Microscopía Electrónica de Rastreo , Smegmamorpha/parasitología , Caracoles/parasitologíaRESUMEN
The life history of the trematode Pygidiopsis macrostomum Travassos, 1928 is described for the first time. Rediae and cercariae were obtained from naturally infected snails Heleobia australis (d Orbigny), a new first intermediate host. Metacercariae were found encysted in the mesenteries of three naturally infected guppies, Phalloptychus januarius (Hensel), Jenynsia multidentata (Jenyns) (new host records) and Poecilia vivipara Bloch and Schneider. Experimental infections were successfully completed in the intermediate hosts H. australis and Poe. vivipara reared in the laboratory and hamsters Mesocricetus auratus Waterhouse were utilised as a definitive host.
Asunto(s)
Heterophyidae/crecimiento & desarrollo , Estadios del Ciclo de Vida/fisiología , Mesocricetus/parasitología , Poecilia/parasitología , Caracoles/parasitología , Animales , Cricetinae , Heterophyidae/ultraestructura , Microscopía Electrónica de Rastreo , Poecilia/clasificación , Estaciones del Año , Caracoles/clasificaciónRESUMEN
The life history of the trematode Pygidiopsis macrostomum Travassos, 1928 is described for the first time. Rediae and cercariae were obtained from naturally infected snails Heleobia australis (d´Orbigny), a new first intermediate host. Metacercariae were found encysted in the mesenteries of three naturally infected guppies, Phalloptychus januarius (Hensel), Jenynsia multidentata (Jenyns) (new host records) and Poecilia vivipara Bloch and Schneider. Experimental infections were successfully completed in the intermediate hosts H. australis and Poe. vivipara reared in the laboratory and hamsters Mesocricetus auratus Waterhouse were utilised as a definitive host.
Asunto(s)
Animales , Cricetinae , Heterophyidae/crecimiento & desarrollo , Estadios del Ciclo de Vida/fisiología , Mesocricetus/parasitología , Poecilia/parasitología , Caracoles/parasitología , Heterophyidae/ultraestructura , Microscopía Electrónica de Rastreo , Poecilia/clasificación , Estaciones del Año , Caracoles/clasificaciónRESUMEN
The trematode Acanthocollaritrema umbilicatum Travassos, Freitas and Bührnheim 1965 is redescribed and data on its life cycle are provided for the first time. Adults were obtained from the common snook, Centropomus undecimalis (Bloch 1792), and both rediae and cercariae from the snail Heleobia australis (d'Orbigny 1835), a new intermediate host. Metacercariae were found encysted among the scales, fins, and musculature and in the buccal cavity of naturally infected fishes, Poecilia vivipara Bloch and Schneider, 1801, Jenynsia multidentata (Jenyns 1842), and Phalloptychus januarius (Hensel 1868), all new intermediate hosts. The examination of the type and freshly obtained adults of A. umbilicatum has shown that they possess 54-64 circumoral spines, in a double row. Experimental infections were achieved in the intermediate hosts H. australis and P. vivipara.
Asunto(s)
Perciformes/parasitología , Caracoles/parasitología , Trematodos/crecimiento & desarrollo , Animales , Enfermedades de los Peces/parasitología , Peces/parasitología , Boca/parasitología , Músculos/parasitología , Trematodos/aislamiento & purificación , Infecciones por Trematodos/parasitologíaRESUMEN
The heterophyid trematode Ascocotyle (Ascocotyle) felippei Travassos, 1928, is redescribed and new data on its life cycle are provided, based on types and metacercariae found in the heart bulb and gills of naturally infected guppies, Poecilia vivipara (new fish intermediate host), from a coastal lagoon in Rio de Janeiro, Brazil. Examination of the type and all voucher specimens of A. (A.) felippei collected by Travassos in the type host and locality in Brazil has shown that they possess only 32 (16 + 16) circumoral spines, rather than 36 (18 + 18) spines as previously reported. Based on the identical number and arrangement of circumoral spines, shape of the body, the presence of a long preoral lobe and posterior muscular prolongation of the oral sucker, short and wide ceca, a simple gonotyl lacking refractile bodies, and the site of infection of metacercariae (predominantly heart bulb), A. (A.) puertoricensis Price, 1932 and A. (A.) tenuicollis Price, 1935, are proposed as new synonyms of A. (A.) felippei.
Asunto(s)
Enfermedades de los Peces/parasitología , Heterophyidae/anatomía & histología , Poecilia/parasitología , Infecciones por Trematodos/parasitología , Animales , Enfermedades de las Aves/parasitología , Aves , Brasil , Heterophyidae/crecimiento & desarrollo , Heterophyidae/ultraestructura , Microscopía Electrónica de Rastreo/veterinaria , Microscopía por Video/veterinariaRESUMEN
Pygidiopsis pindoramensis Travassos, 1928, is redescribed from the holotype and specimens obtained from experimental infections of hamsters with metacercariae of the naturally infected poeciliids Poecilia vivipara and Phalloptychus januarius from Rio de Janeiro, Brazil. Ascocotyle (Phagicola) pindoramensis (Travassos, 1928) n. comb. is proposed, based on the presence of a solid, tapering muscular posterior prolongation of the oral sucker and Ascocotyle (Phagicola) mollienisicola (Sogandares-Bernal and Bridgman, 1960) is synonymized with A. (P.) pindoramensis because of the identical morphology and measurements of adults and metacercariae, similar spectrum of fish intermediate hosts (poeciliids), and the same site of infection of the metacercariae. Trematodes designated as Pygidiopsis pindoramensis, previously reported from Argentina and Mexico, represent another species of Pygidiopsis Looss, 1907, because they possess circumoral spines and their oral sucker is devoid of the posterior muscular prolongation. Data on the surface morphology of metacercariae and adults of A. (P.) pindoramensis are inferred from scanning electron microscopy observations.
Asunto(s)
Trematodos/clasificación , Trematodos/ultraestructura , Animales , Cricetinae , Ciprinodontiformes , Enfermedades de los Peces/parasitología , Mesocricetus , Microscopía Electrónica de Rastreo/veterinaria , Poecilia , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/veterinariaRESUMEN
Technetium-99 (99m Tc) is a radionuclide that has negligible enviromnental impact, is easily available, inexpensive and can be used as a radioactive tracer in biological experiences. In order to know the mode of action of sodium phenobarbital in moving adult Schistosoma mansoni worms from mesenteric veins to the liver, we labelled sodium phenobarbital (PBBT) with 99m Tc and a biodistribution study in infected and non-infected Swiss mice was performed. The PBBT was incubated with stannous chloride used as reducing agent and with 99m Tc, as sodium pertechnetate. The radioactivity labelling (per cent) was determined by paper ascending chromatography performed with acetone (solvent). The 99m Tc-PBBT was administered by intraperitoneal route to Swiss mice infected eight weeks before. The animals were perfused after diferent periods of time (0,1,2,3,4 hr) when blood, spleen, liver, poral, vein, mesenteric veins, stomach, kidneys and adult worms were isolated. The radioactivity present in these samples was counted in a well counter and the percentage was determined. The radioactivity was mainly taken up by the blood, kidney, liver and spleen. No radioactivity was found on the worms. We concluded that the worm shiff was due to an action on the lost of the sodium phenobarbital.